bluuebunny/crossref_metadata_2025 huggingface dataset:
CHROMOSIN, A DESOXYRIBOSE NUCLEOPROTEIN COMPLEX OF THE CELL NUCLEUS
Authors: Mirsky A. E. , Pollister A. W.
Published: May 2004

A desoxyribose nucleoprotein complex, which we have referred to as a chromosin, has been prepared from a great variety of cells, mainly animal but also plant and bacterial. A chromosin is derived from the cell nucleus. In the course of preparation precautions have been taken to prevent contamination by cytoplasmic constituents. To assure the nuclear origin of all components of chromosin, nuclei have in several instances been isolated before extraction was begun. Because of the precautions taken, chromosins do not contain detectable quantities of ribose nucleoproteins; but, incidentally, extraction of ribose nucleoproteins, free of desoxyribose compounds, has also been described in this paper.

A typical chromosin contains 3 components: desoxyribose nucleic acid, histone, and non-histone protein. The nucleic acid, being highly polymerized, is exceedingly viscous when dissolved and fibrous when precipitated. Histone and non-histone protein differ from each other in a number of ways, of which one of the most definite is that whereas a histone contains no more than traces of tryptophane, the non-histone protein of chromosin contains nearly 1 per cent of tryptophane. In neutral physiological saline both proteins can combine with nucleic acid. With the isolation of chromosins from so many different kinds of cells, it can now be seen that (contrary to the view expressed by Kossel) histones are present in most animal cells and at least in some plant and bacterial cells.

Chromosin prepared from the Type III pneumococcus is active in transforming the type of a pneumococcus culture. It has been pointed out that it is not yet known whether or not protein is a necessary constituent of the transforming agent.

To extract chromosin from a cell M NaCl is used. When dissolved in M NaCl the nucleic acid and histone components of a chromosin are to a considerable extent dissociated. They are not dissociated when the chromosin is dissolved in 0.02 M NaCl, but in this medium a partial depolymerization of the nucleic acid occurs.

A chromosin should certainly not be considered to be a definite chemical compound. It is a complex extracted from chromatin, which is itself a complicated nuclear structure. And in the course of extraction, it need hardly be said, the structure of chromatin has been considerably changed. To avoid complications it has been considered an advantage in this work to begin with isolated nuclei, and it would clearly be a further simplification to begin chemical procedures only after the chromosomes themselves have been isolated. This is now being accomplished, and it is found that the methods described in this paper are of value in learning how the substances present in a chromosin are put together in a chromosome.
THE ACTIVATION OF PLASMINOGEN BY CHLOROFORM
Authors: Christensen L. R.
Published: May 2004

1. Treatment of serum with chloroform results in immediate inactivation of the protease inhibitor present.

2. Following a lag period of less than one to several days, proteolytic activity begins to appear in the chloroform-treated serum. Activity increases over a period of several days and then begins to diminish gradually. At about the time when the spontaneous activity begins to diminish, the total proteolytic activity of the preparation also begins to fall until finally the two curves coincide.

3. Chloroform treatment of serum appears to result in some destruction of plasminogen because not only is the total proteolytic activity of the chloroform-treated serum less than that of the serum before chloroform treatment, but the maximum spontaneous activity that develops is only about one-half the total proteolytic activity of serum before treatment with chloroform.

4. The spontaneous activation of plasminogen which occurs following removal of inhibitor appears to be autocatalytic in nature.

5. In the presence of active plasmin, both plasmin and plasminogen are destroyed.
SALTANT PRODUCTION BY WAVE LENGTHS OF VISIBLE AND LONG ULTRAVIOLET MONOCHROMATIC IRRADIATION, AND A COMPARISON WITH SALTANTS PRODUCED BY SHORT WAVE LENGTHS OF MONOCHROMATIC ULTRAVIOLET IRRADIATION IN THE FUNGUS CHAETOMIUM GLOBOSUM
Authors: Ford Joan Munro
Published: May 2004

1. Saltants have been produced in the fungus Chaetomium globosum by longer wave lengths than previously reported—by 365 mµ and by a visible line 404 mµ.

2. Absence at these wave lengths of the K saltant, which is so abundant at short wave lengths, is marked.

3. Ratio of percentage irradiated spores germinating to control spores germinating decreases from 83 per cent at 265 mµ, a short ultraviolet wave length, to 57 per cent at 404 mµ, a visible violet wave length.
THE OXYGEN CONSUMPTION ASSOCIATED WITH GROWTH IN ESCHERICHIA COLI AND THE EFFECT OF SULFATHIAZOLE AND OF n-PROPYL CARBAMATE ON IT
Authors: Armstrong Florence H. , Fisher Kenneth C.
Published: May 2004

1. The rate of oxygen consumption by E. coli has been observed both in the presence and absence of ammonia which substance is used by this organism in these experiments as the sole source of nitrogen for growth.

2. After the ammonia has been completely taken up in a culture of E. coli, the rate of oxygen consumption by the culture is observed to fall rapidly. It becomes relatively constant again at a rate approximately 45 per cent of that existing immediately prior to the exhaustion of the nitrogen source. It appears that the fixation of ammonia, that is, growth, requires approximately 55 per cent of the oxygen consumed by the growing cell.

3. Inhibition of the oxygen consumption which is associated with ammonia fixation, by both sulfathiazole (ST) and n-propyl carbamate (PC) closely parallels the inhibition of growth by these compounds (as measured by viable cell counts, etc.).

4. The concentrations of ST and PC which inhibit growth exert little or no inhibitory effect on the rate of oxygen consumption by cells after the rate has fallen to the resting value.

5. It is pointed out that the above observations would be adequately accounted for if growth depended on a discrete fraction of the total oxygen consumption of the growing cell.

6. It is noted that PC, but not ST, has a significant accelerating effect on the oxygen consumption of the resting cell; and that for a given inhibition of growth, PC produces less inhibition of the total oxygen consumption of the cells, than does ST. The latter of these two observations would follow from the former if the resting oxygen consumption were a discrete entity.
METABOLIC INTERMEDIATES IN ADAPTIVE FERMENTATION OF GALACTOSE BY YEAST
Authors: Reiner John M.
Published: May 2004

Pyruvic acid, which is known to be an intermediate of glucose fermentation, was added to yeast during adaptation to galactose fermentation. It was found to neutralize the inhibition by sodium fluoride, and to decrease the apparent time of adaptation from 90 to about 45 or 60 minutes. In control experiments, it was shown that intact yeast is unable appreciably to ferment or decarboxylate alone, although it oxidizes the compound readily.

Experiments in which galactose and pyruvate were added at various times and in different orders were used to eliminate the possible complications of the rates at which these compounds penetrate the cells. Under these conditions, it was not possible to reduce the time of adaptation below 45 minutes. It was concluded that the rôle of added pyruvate was to serve as a source of acetaldehyde, which in turn could accept hydrogen and be reduced to alcohol. Substances, such as triose phosphate, which could serve as hydrogen donors were not produced from galactose in appreciable quantities until 45 minutes had elapsed. This time was therefore inferred to be the true adaptation time, during which the first synthesis of adaptive enzymes occurred.

Some determinations of the distribution of phosphorylated intermediates at various stages during the adaptive process were carried out. It was found that ATP, which usually serves to phosphorylate hexoses, accumulates during the preadaptive phase, diminishes rapidly after 60 minutes, and subsequently increases once more. The source of the ATP phosphate appeared to be PPA or triose phosphate initially present in the cells. It was inferred that the adaptive enzyme was concerned with the phosphorylation of galactose and the conversion of the phosphate ester to a glucose ester, which could then be fermented by the normal enzymes of the cell.

Added ATP was found to stimulate adaptation to a considerable extent, but did not shorten the time of adaptation below 75 minutes. This seemed consistent with the rôle of ATP as a phosphate donor for galactose. Creatine was found to inhibit adaptation to some degree, in agreement with its known ability to act as a competitive phosphate acceptor.

It was demonstrated that yeast produces, during and after adaptation, substances which shorten the apparent adaptation time of fresh samples of yeast. In agreement with our other findings, it appeared that such substances were not formed before about 45 minutes. They are probably not metabolic intermediates, and may be identical with the adaptive principle which can be extracted from adapted cells.
STUDIES ON THE PHYSIOLOGICAL EFFECTS OF NON-POLAR-POLAR ORGANIC ELECTROLYTES
Authors: Höber Rudolf
Published: May 2004

1. The commonly used detergents have a poisonous effect, which is due to the non-polar-polar configuration of their organic anion. The non-polar organophilic half of the ion is built up by a long chain of alkyl radicals (8 to 18 carbon atoms), the polar hydrophilic half by a sulfonate or sulfate. If brought into contact with the organic surface membrane of a cell, this structure, due to the strong attachment of the alkyl chains to its surface, and due to the pull of the hydrophilic part towards the surrounding water, is subjected to a heavy stress terminating in tearing to pieces the membrane (by denaturing and loosening the membrane components; bacteriolysis, cytolysis). Correspondingly, with frog muscle, one end of which has been treated with the detergent solution, an irreversible negative injury potential is produced.

2. Applying, instead, the compounds bearing short chains of alkyl radicals (1 to 6 carbon atoms), producing less stress on the membrane and correspondingly a slighter derangement of its architecture, a reversible positive resting potential appears. This is interpreted to be the effect of the non-polar part of the anion, which, due to its surface activity, intrudes into the pores of the membranes, notwithstanding the negative charge of their walls.

3. The short chained detergents seem to be replaceable by various organic "semidetergents," the organophilic behavior of their anion being represented by a slight chemical affinity (NH2), the hydrophilic by the effect of a carboxyl group (COO) instead of sulfate or sulfonate. The effect of the semidetergents on muscle is a positive reversible potential. Their physiological significance may be visualized as a functional activation.
PROTAMINE PURIFICATION OF STREPTOKINASE AND EFFECT OF pH AND TEMPERATURE ON REVERSIBLE INACTIVATION
Authors: Christensen L. R.
Published: May 2004

1. Treatment of crude concentrates of streptokinase with protamine results in removal of about 90 per cent of the nitrogenous material, including nucleic acid and protease inhibitor, with little or no loss of activity.

2. Streptokinase solutions undergo reversible inactivation with changes in pH. The rate and extent of inactivation are dependent on pH, being greatest over a very narrow range about pH 5. The rate and extent of inactivation are also a function of temperature, both increasing with the temperature of incubation. The rate of reactivation is a function of pH and temperature, increasing as either is raised. However, as the temperature is raised above about 23°C., or the pH above about 9, a secondary, irreversible inactivation of streptokinase occurs.
PROLYTIC ION EXCHANGES PRODUCED IN HUMAN RED CELLS BY METHANOL, ETHANOL, GUAIACOL, AND RESORCINOL
Authors: Ponder Eric
Published: May 2004

When the washed red cells of heparinized human blood are exposed at 4°C. to methanol, ethanol, guaiacol, or resorcinol in hypolytic concentrations in isotonic NaCl, the prolytic loss of K at the end of 20 hours varies from about 25 per cent of the initial K content of the cells in the case of 3.1 M methanol to about 55 per cent of the initial K in the case of 0.04 M resorcinol. As in the case of the prolytic losses observed with other lysins, the K loss is rapid at first and then slows down so that what appears to be a new steady state is reached logarithmically.

The K lost from the cells during the period of the prolytic loss is replaced by an approximately equivalent amount of Na, derived from the isotonic NaCl in which the cells are suspended. The Na which enters can be replaced by K by washing the cells in isotonic KCl, and this K can again be replaced by Na by washing the cells in isotonic NaCl. The remainder of the cell K., i.e. the K which was not lost during the period of the prolytic loss, is retained in the cell unaffected by these washing procedures.

The capacity of red cells for undergoing disk-sphere transformations is scarcely affected by their having been exposed to hypolytic concentrations of methanol, ethanol, guaiacol, or resorcinol in isotonic NaCl, and their resistance to osmotic hemolysis and to lysis by saponin and digitonin is altered only in minor respects even when as much as 50 per cent of the cell K has been exchanged for Na.

Some restriction to the movement of K between the cell and its environment is apparently modified irreversibly when the cell is exposed to hypolytic concentrations of lysins, and the modification is such that only a fraction of the cell K is affected, the fraction being a function of the lysin concentration, the duration of its action, and other factors. A modification of some part of the cell structure and of the properties dependent on its integrity is probably involved: K may be lost more readily from some cells than from others, from some parts of the cell more readily than from other parts, or the explanation may lie in changes in the extent to which Hb binds ions or in modifications of metabolic processes.
THE EFFECT OF ENVIRONMENTAL POTASSIUM AND CALCIUM CONCENTRATIONS ON THE RECOVERY OF THE ACTION POTENTIAL AND RELATED FUNCTIONS OF NERVE
Authors: Graham Helen Tredway , Blair H. A.
Published: May 2004

1. When the Ringer's solution applied to isolated frog sciatic nerve contains K+ in concentrations greater than 2 x standard, the height of the spike and of the after-potential is decreased, as is the duration of the after-potential; recovery of height and of excitability following response is delayed; degree and duration of supernormal excitability are decreased; postcathodal depression and postanodal enhancement are increased and prolonged.

2. The nerve functions just listed in general all change in the opposite direction when exposed' to increased environmental [Ca++]. (4.5–20 x standard) or decreased [K+] (0.05–0.2 x standard). The effects of decreased [Ca++] (0.20–0.25 x standard) are indeterminate.

3. When [K+] and [Ca++] are both greater than 2 x standard, whatever the ratio between the concentrations the effects characteristic of high [K+] eventually predominate. However, these effects, except for those involving spike height, are preceded by effects characteristic of high [Ca++] when this cation is present in sufficient excess.

4. When [K+] and [Ca++] are reduced to equal low levels (0.1–0.2 x standard), effects characteristic of low [K+] and high [Ca++] are obtained.

5. The experimentally determined order of ability of the environments to produce changes characteristic of high K+ (which is the reverse of the order of their ability to produce changes characteristic of high [Ca++]), is not the order of their K+ or Ca++ concentrations, nor of the ratio between these concentrations (Table II).

6. The results may be explained by the assumption that the functions investigated are all to greater or less degree controlled by (1) the [K+]/[Ca++] ratio and (2) the K+ concentration, at least when this exceeds a critical level. Control by [K+] is more effective for spike height and its recovery after stimulation than for the other functions. The special rôle of K+ is attributed to an unknown specific effect of this ion which Ca++ is unable to oppose. It is suggested that this K+ effect in general becomes marked on the frog nerve functions investigated when the K+ concentration is somewhat above 2 x standard, while the [K+]/[Ca++] ratio must be changed by a factor of 4 or more before it exerts a definite effect on these functions.

7. In standard and in modified cationic environments, nerve functions vary in the ease with which they manifest changes characteristic of high [K+] or of high [Ca++].

8. The after-potential functions are less completely controlled by the cationic environment than are the other functions investigated.
THE PREADAPTIVE OXIDATION OF GALACTOSE BY YEAST
Authors: Reiner John M. , Spiegelman S.
Published: May 2004

A preadaptive purely aerobic utilization of galactose by yeast cells has been demonstrated. Hence, the adaptation by yeast to galactose is not to its utilization per se, but specifically to its metabolism by a glycolytic mechanism. An examination of this preadaptive oxidation of galactose reveals that it has many characteristics in common with the endogenous metabolism of yeast. Included among these are the similarities of the R.Q. values and the response of the QOO2 and QCOCO2O2 to KCN and iodoacetic acid. Further, a competitive interaction appears to exist between the endogenous respiration and the preadaptive oxidation of the galactose. The latter can replace the endogenous respiration as a source of energy for the adaptation to the fermentation of the galactose. Carbon balance studies of the galactose oxidation revealed that polysaccharide could be formed as a result of this metabolism during the preadaptive period.

Non-adaptable cells were also found to possess the capacity to oxidize galactose in the complete absence of any ability to metabolize it anaerobically.

The significance of these findings for the biochemistry and physiology of the adaptation is discussed.
THE BIOSYNTHESIS OF C13 COMPOUNDS
Authors: Livingston L. G. , Medes Grace ,   With the Technical Assistance of Alice Shapiro
Published: May 2004

1. Starch, containing 7.05 atom per cent C13 excess has been produced in the mesophyll cells of bean leaves, starting with C13O2 containing 7.26 atom per cent C13 excess. Approximately 67 per cent of the C13 taken up by the leaves was determined in the starch fraction.

2. The soluble carbohydrate, containing 6.72 atom per cent C13 excess, accounts for approximately 23 per cent of the C13 taken up by the leaves. The remainder was principally in the coarse tissue fragments fraction (9.73 per cent of the C13 utilized).

3. The apparatus and procedures used in this experiment are described.
STUDIES ON THE SONIC TREATMENT OF TOBACCO MOSAIC VIRUS
Authors: Oster Gerald
Published: May 2004

Centrifugally purified samples of tobacco mosaic virus were subjected to intense sound vibrations of 9,000 cycles per second for 0, 2, 8, 16, 32, and 64 minutes. The viscosity and stream birefringence of the samples decreased with time of sonic treatment, but no chemical changes were found. Electron micrographs of the samples show that the particles are broken perpendicular to their long axis. In the untreated sample 62 per cent of the particles are about 280 mµ in length. As sonic treatment continued, the number of particles of this length decreased exponentially with time, the number half this length increased and then decreased, and the number of quarter length particles subsequently increased and then decreased. The biological activity of the samples, as determined by the half leaf lesion method, decreased exponentially with time of sonic treatment with a rate constant given by k = 0.13 min.–1. A correlation exists between the size distributions and biological activity and shows that only the particles of length 280 mµ are the biologically active units.

Tobacco mosaic virus particles can be made to aggregate end-to-end when the material is heated at its isoelectric point and reheated after being brought back to pH 7. Material which was not sonic treated and was made to aggregate showed reduced biological activity, but the activity was increased when the aggregated material was subjected to strong mechanical stirring. Material which was sonic treated for 32 minutes and which was made to aggregate showed the same biological activity as the material which was sonic treated but not aggregated.
BACTERIOPHAGE FORMATION WITHOUT BACTERIAL GROWTH
Authors: Price Winston H.
Published: May 2004

Bacteriophage will increase 100,000 times in Staphylococcus muscae cultures whose multiplication has been completely inhibited by penicillin.
INTERACTIONS BETWEEN ENZYME-FORMING SYSTEMS DURING ADAPTATION
Authors: Spiegelman S. , Dunn Reba
Published: May 2004

Experiments on enzymatic adaptations in yeast to galactose and maltose under various conditions are examined. The pertinent facts established may be summarized as follows:—

1. The presence of exogenous nitrogen stimulates the rate of adaptation and raises considerably the attainable level of enzyme activity.

2. This stimulation is absent if the cells are unable to assimilate the added nitrogen.

3. Competitive interactions can be exhibited between two adaptive enzyme systems induced either serially or simultaneously in the same cell.

4. A similar kind of interaction was observed between an adaptive and a so called "constitutive" enzyme.

5. The presence of exogenous nitrogen modifies greatly the nature and extent of the interaction between the enzyme-forming systems.

The significance of these results to our understanding of the mechanism of the modification and maintenance of cellular enzymatic constitution is discussed. The validity of the distinction between "constitutive" and "adaptive" enzymes is reexamined in the light of the data presented.
STUDIES ON A NEW METABOLITE AND ITS OXIDATION IN THE PRESENCE OF ASCORBIC ACID
Authors: Bernheim Frederick , Wilbur Karl M. , Fitzgerald Dorothea B.
Published: May 2004

1. A number of tissues, in particular, brain, liver, and kidney, incubated aerobically in vitro as slices or ground suspensions produce a compound which combines with p-aminobenzoic acid in acid solution to form a yellow color.

2. A study of this reaction in rat brain has shown that this compound can be produced when washed boiled brain protein is incubated aerobically with ascorbic acid. The latter acts as a catalyst to break the linkage between the protein and the compound. Oxygen is taken up in the process.

3. A number of aromatic hydroxy compounds such as epinephrine and catechol inhibit the reaction. Cyanide has little or no effect. No reaction occurs anaerobically.

4. The occurrence of the reaction in some animals has been described.
ABNORMAL PROTOPLASMIC PATTERNS AND DEATH IN SLIGHTLY HYPERTONIC SOLUTIONS
Authors: Osterhout W. J. V.
Published: May 2004

Some interesting properties of protoplasm are revealed when slightly hypertonic solutions of sugars or of electrolytes are applied to Nitella.

The chloroplasts contract and the space between them increases and forms a characteristic pattern consisting of clear areas extending lengthwise along the cell and tapering off at both ends.

The development of these areas is irreversible from the start. If the cell is returned to water after plasmolysis begins these areas continue to enlarge in much the same fashion as when no change is made in the external solution. The cell soon dies whether returned to water or left in the plasmolyzing solution. Similar results are obtained with other sugars, with NaCl, CaCl2, and sea water.

Similar reactions are also brought about by strong ingoing or outgoing currents of water. This suggests that mechanical action may be chiefly responsible for the result and this idea is in harmony with other facts. It seems possible that the retraction of the protoplasm from the cellulose wall may disturb the delicate non-aqueous film which covers the outer surface of the protoplasm and thus produce injury. Such an effect might take place even without visible retraction if the injury occurred in protoplasmic projections extending into the cellulose wall.

A study of this behavior may throw light on the nature of the protoplasmic surface and on the properties of protoplasmic gels as well as on the process of death. An understanding of the mechanism involved may help to explain the action of hypertonic solutions in other cases as, for example, in the artificial parthenogenesis of marine eggs.
THE REACTION BETWEEN ACTOMYOSIN AND ADENOSINE TRIPHOSPHATE
Authors: Mommaerts W. F. H. M.
Published: May 2004

1. A study is made of the effect of adenosine triphosphate (ATP) upon the viscosity of solutions of actomyosin in 0.5 M KCl.

2. The observed effects are discussed in terms of an initial drop of the viscosity (viscosity response) and its subsequent slow reversal (recovery effect). The latter is ascribed to a decrease in the ATP concentration through enzymatic hydrolysis.

3. The recovery effect is inhibited by Mg, activated by Ca, in accordance with the effect of these ions on the activity of myosin-ATPase.

4. The viscosity response is not inhibited, probably promoted by Mg. It is not promoted, probably inhibited by Ca.

5. The viscosity response is induced not only by ATP, but to a certain extent also by inosinetriphosphate, inorganic triphosphate, and inorganic pyrophosphate, not by adenosine diphosphate or monophosphate.

6. The viscosity response could be obtained with enzymatically inactive myosin.

7. It is concluded that the effect of ATP upon myosin does not depend on its enzymatic hydrolysis.
THE SYNTHESIS FROM VITAMIN A1 OF "RETINENE1" AND OF A NEW 545 mµ CHROMOGEN YIELDING LIGHT-SENSITIVE PRODUCTS
Authors: Wald George
Published: May 2004

Ball, Goodwin, and Morton (1946) have reported that vitamin A1 in contact with solid manganese dioxide is transformed slowly into a substance which displays spectroscopic properties of retinene1. The latter is known to be the precursor of vitamin A1 in the rhodopsin cycle of the retinal rods. The synthetic product is here referred to as "retinene1."

In the present experiments this observation is confirmed. The procedure is recast in the form of a chromatographic oxidation. Manganese dioxide is packed in a column, vitamin A1 solution poured in at the top, and the product drawn off in the filtrate. Depending upon the proportions of manganese dioxide and vitamin A1, the product is either "retinene1," or a new substance which yields with antimony chloride a wine-red product with maximal absorption at 545 mµ (545 mµ chromogen). This procedure is an example of a potentially important class of chromatographic reactions.

The synthetic "retinene1" is virtually identical with the natural substance in absorption spectrum and antimony chloride reaction. It lacks the pH indicator properties of crude natural retinene1.

The 545 mµ chromogen possesses absorption maxima at 380 and 290 mµ in chloroform; at 376 and 290 mµ in ethanol; and at 361 and 277 mµ in hexane. It is non-fluorescent. It has no acidic character, but on the contrary is mildly basic, being extracted from hexane by sulfuric or hydrochloric acids to form orange-red products. In partition between petroleum ether and aqueous methanol it is highly hypophasic. It is adsorbed strongly on calcium carbonate.

Certain peculiarities in spectral behavior indicate the presence of a carbonyl group in the 545 mµ chromogen, and support Morton's proposal that such a group occurs in retinene1. Other properties of the 545 mµ chromogen indicate hydroxyl groups. This substance therefore appears to be a hydroxy-carbonyl derivative of vitamin A1.

The red products which the 545 mµ chromogen forms with antimony chloride or with sulfuric or hydrochloric acids are all markedly light-sensitive. They appear to be formed by the condensation of two molecules with loss of water; and to bear a close generic relation to the prosthetic groups of the visual photopigments.
STUDIES ON THE PHYSIOLOGICAL EFFECTS OF NON-POLAR-POLAR ORGANIC ELECTROLYTES
Authors: Höber Rudolf , Langston Mary , Strausser Helen , Macey Robert
Published: May 2004

In a previous paper it has been shown that the nonpolar-polar anionic detergents can be divided into two main groups. One chemically characterized by a relatively long chain of non-polar alkyl groups, which in solution are in contact with one end of a muscle and, locally adhering to it, produce a permanent negative injury potential. This is generally accompanied by a loss of excitability. The second group, distinguished by a relatively short chain of non-polar alkyl groups acts reversibly, ordinarily preserves the excitability and, in contrast to the first group, produces locally a reverse positive potential. For reasons mentioned before, this appears likely to correspond to an increased activity.

These concepts have been tested in this second paper. The measurements of the resting potentials of muscles have been supplemented by measurements on frog sciatics with the result that there are brought about, again by the detergents with long alkyl chains, regular irreversible negative resting potentials and with the short chain compounds reversible positive potentials are aroused. Furthermore, in addition there appeared the hardly expected result that muscle stimulated in the presence of short chain detergents responded with an even higher contraction. We have endeavored to explain this on the basis of general considerations concerning the physical chemistry of the excitatory process.

More direct evidence of this rise of excitability under the influence of the short chain non-polar-polar detergents will be presented in the next papers on studies concerning chronaximetric measurements on nerve, referring particularly to the semidetergents, and concerning the effects of detergents in general upon the heart beat of a clam.
A METHOD FOR THE PREPARATION OF "PROTEASE-FREE" CRYSTALLINE RIBONUCLEASE
Authors: McDonald Margaret R.
Published: May 2004

A method is described for the preparation of crystalline ribonuclease free from all measurable traces of proteolytic enzymes.
THE CHANGE IN OSMOTICALLY INACTIVE FRACTION PRODUCED BY CELL ACTIVATION
Authors: Shapiro Herbert
Published: May 2004

1. Resting and activated eggs of the sea urchin Arbacia punctulata were swollen in hypotonic sea water (60, 70, 80, and 90 per cent), and allowed to attain equilibrium volumes (Figs. 1 and 2).

2. Both fertilized and unfertilized eggs obey the Boyle-van't-Hoff law, but the value for b, the "osmotically inactive fraction" or non-swellable volume, was different for the two, averaging in the cases studied 7.3 per cent for unfertilized and 27.4 per cent for fertilized.

3. On activation, the eggs of the sea urchin undergo a definite increase in total cell volume, of approximately 2.7 per cent.

4. Some evidence is adduced for the possibility that the alteration in cell volume and in o.i.f. may depend upon the species in question.

5. A parallelism between change in b and alteration of respiratory metabolism in Arbacia, Chaetopterus, and Arbacia fragments is pointed out. This requires further investigation in other species to establish generality.

6. Equations for the calculation of the point at which osmotic pressures and cell volumes are identical for unfertilized and fertilized eggs are included.

7. A mechanical analogue of the phenomena is introduced (Fig. 3).
NITRATE REDUCTION AND ASSIMILATION IN CHLORELLA
Authors: Cramer Marian , Myers Jack
Published: May 2004

1. Nitrate reduction and assimilation have been studied in Chlorella pyrenoidosa under growth conditions by observing effects on the CO2/O2 gas exchange quotient.

2. During assimilation of glucose in the dark, nitrate reduction is noted as an increase in the R.Q. to about 1.6 caused by an increased rate of carbon dioxide production.

3. During photosynthesis at low light intensity nitrate reduction is evidenced by a reduction in the CO2O2 quotient to about 0.7 caused by a decreased rate of carbon dioxide uptake.

4. Chlorella will assimilate nitrogen from either nitrate or ammonia. When both sources are supplied, only ammonia is utilized and no nitrate reduction occurs. It is inferred that under the usual conditions of growth nitrate is reduced only at a rate required for subsequent cellular syntheses. The effect of nitrate reduction on the CO2O2 quotient therefore provides a measure of the relative rate of nitrogen assimilation.

5. Over-all photosynthetic metabolism may be described from elementary analysis of the cells since excretory products are negligible. The gas exchange predicted in this way is in good agreement with the observed CO2/O2 quotients.
REGULATORY MECHANISMS OF CELLULAR RESPIRATION
Authors: Barron E. S. Guzman , Nelson Leonard , Ardao Maria Isabel
Published: May 2004

Oxidizing agents of sulfhydryl groups such as iodosobenzoate, alkylating agents such as iodoacetamide, and mercaptide-forming agents such as cadmium chloride, mercuric chloride, p-chloromercuribenzoate, sodium arsenite, and p-carboxyphenylarsine oxide, added in small concentrations to a suspension of sea urchin sperm produced an increase in respiration. When the concentration was increased there was an inhibition. These effects are explained by postulating the presence in the cells of two kinds of sulfhydryl groups: soluble sulfhydryl groups, which regulate cellular respiration, and fixed sulfhydryl groups, present in the protein moiety of enzymes. Small concentrations of sulfhydryl reagents combine only with the first, thus producing an increase in respiration; when the concentration is increased, the fixed sulfhydryl groups are also attacked and inhibition of respiration is the consequence.

Other inhibitors of cell respiration, such as cyanide and urethanes, which do not combine with —SH groups, did not stimulate respiration in small concentration.
THE CHEMICAL STATE OF THE CALCIUM REACTING IN THE COAGULATION OF BLOOD
Authors: Quick Armand J. , Stefanini Mario
Published: May 2004

1. The widely accepted theory that calcium participates in the coagulation mechanism in the form of Ca++ and acts as a catalyst is not in accord with several important experimental findings:

(a) The anticoagulant action of sodium oxalate is much slower than the precipitation of ionized calcium as the oxalate salt.

(b) Sodium citrate begins to depress prothrombin activity at a concentration at which ionized calcium is still present. The inability of tricalcium phosphate to adsorb prothrombin from citrated plasma indicates that citrate forms a complex with prothrombin and it is postulated that prothrombin is thereby inactivated.

(c) In plasma which is decalcified, i.e. in which the Ca++ is markedly reduced, the labile factor of prothrombin rapidly decreases. A concentration of 0.01 M sodium citrate sufficient to inhibit coagulation does not depress Ca++ enough to cause diminution of the labile factor, whereas when the concentration is increased to 0.02 M the labile factor decreases as rapidly as in oxalated plasma.

2. It is postulated that calcium functions in coagulation not as Ca++ but as combined with a component which is part of the prothrombin complex that is not adsorbed by tricalcium phosphate. A concentration of sodium citrate just sufficient to inhibit coagulation is not enough to remove calcium from the essential prothrombin component. The primary anticoagulant action of sodium citrate is therefore not decalcification but antiprothrombic.

3. It has been shown that citrated plasma is basically different from oxalated plasma in several important aspects. Unless cognizance is taken of these differences, serious errors and misinterpretations of experimental findings may be made.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H.
Published: May 2004

1. Experiments carried out in Fildes' synthetic medium show that there is a competition between the host and virus for a substance present in acid-hydrolyzed casein. This substance appears to be essential for the multiplication of the virus but not for the host.
CRYSTALLIZATION OF SALT-FREE CHYMOTRYPSINOGEN AND CHYMOTRYPSIN FROM SOLUTION IN DILUTE ETHYL ALCOHOL
Authors: Kunitz M.
Published: May 2004

Chymotrypsinogen and chymotrypsin crystallize readily from dilute solutions of ethyl alcohol in the absence of salts. The crystals formed in the presence of alcohol differ in appearance from those formed in the presence of ammonium sulfate. Chymotrypsinogen yields well formed polyhedrons instead of fine needles usually produced in ammonium sulfate solution. Chymotrypsin yields fine needles in the presence of alcohol and rhombohedrons in the presence of ammonium sulfate. The enzymatic properties of the crystals formed in the presence of alcohol are identical with those of the crystals isolated in the presence of ammonium sulfate.
TRACER STUDIES OF NITROGEN ASSIMILATION IN YEAST
Authors: Abrams Richard , Hammarsten E. , Reichard P. , Sperber E.
Published: May 2004

By using N15 as a tracer the assimilation of ammonia by the yeast, Torulopsis utilis, has been studied. It has been shown that:

1. There was no measurable incorporation of N in the protein or polynucleotide purine of carbon-starved yeast.

2. When ammonia is added to nitrogen-starved yeast there is a long lag period before division begins during which the yeast rapidly synthesizes protein, this process being accompanied by a turnover of polynucleotide purine. There was no significant dilution of the N15H4+ of the medium by ordinary NH4+.

3. When yeast containing N15 is allowed to divide and grow in ordinary ammonia, the total amount of N15 in the yeast remains constant. The dicarboxylic amino acids are most diluted, while arginine and nucleic acid guanine are not diluted at all.
PHAGE FORMATION IN STAPHYLOCOCCUS MUSCAE CULTURES
Authors: Price Winston H.
Published: May 2004

1. A non-dialyzable fraction from fresh bakers' yeast stimulates the formation of S. muscae virus in cells in synthetic medium in the log phase of multiplication.

2. A similar fraction was not found in calf thymus, pancreas, or liver.

3. The active substance in this fraction has been partially purified.

4. This substance is taken up by the cells. In the absence of virus the added substance is metabolized to a form no longer available for virus formation.

5. A purified yeast fraction, which stimulates adaptive enzyme formation in yeast, has been found to stimulate virus formation in the S. muscae system.

6. The similarities between the yeast fraction that stimulates adaptive enzyme formation and the yeast fraction that stimulates virus formation are discussed.
THE ACTIVATION OF UREASE
Authors: Hofstee B. H. J.
Published: May 2004

1. It has been shown that the activity of solutions of twice recrystallized urease is reversibly increased by moderate heating and reversibly decreased by storage in the cold, even in the frozen state.

2. Crude extracts of jack bean meal containing potent urease undergo this same type of reversible activation by heating and inactivation by cooling. Dilution has the same potentiating effect on the activity as moderate heating.

As much as a fivefold increase in activity can be obtained when a sample previously inactivated by storage for 24 hours at –10°C. is heated for 5 minutes at 60°C.

3. Solutions of crystalline urease protected by serum albumin and preserved in the cold give a constant "potential" activity over a period of more than 30 days if heated 5 minutes at 60°C. before assay.

4. The data presented have been interpreted to mean that an association between urease molecules (or between urease and other proteins) might occur, resulting in inactivation of the enzyme which would be reversed on dissociation.

5. It has been postulated that the same forces are responsible for the reversible inactivation brought about by standing at temperatures above or below the freezing point.
THE REDUCTION OF RETINENE1 TO VITAMIN A1 IN VITRO
Authors: Wald George , Hubbard Ruth
Published: May 2004

In the surviving vertebrate retina the retinene1 liberated by bleaching rhodopsin is converted quantitatively to vitamin A1. Recent chemical studies have indicated that in this process the aldehyde group of retinene1 is reduced to the primary alcohol group of vitamin A1 (Morton; Wald).

Some time ago we brought this reaction into a cell-free brei prepared from cattle retinas. The retinas were frozen, desiccated, ground, and exhaustively extracted with petroleum ether; the resulting powder, stirred in neutral buffer solution and exposed to light, converted its retinene1 completely to vitamin A1.

Some time ago also we observed that fresh rhodopsin solutions exhibit a special type of fading in darkness following exposure to light, which is absent from the same solutions after aging. We have confirmed Bliss's identification of this reaction as the conversion of retinene1 to vitamin A1.

The system which reduces retinene1 is fractionated anatomically in the retinal rods. The outer segments of the rods, broken off from the underlying retinal tissue, are unable to convert their retinene1 to vitamin A1. In the presence of a water extract of crushed retina they do perform this conversion. On the other hand the retinal tissue from which a water extract was taken has lost this capacity. Such washed retinal tissue is reactivated by returning the washings to the solid material.

The activating effect of retinal washings on isolated outer limbs or washed retina is duplicated by a boiled muscle juice. This in turn can be replaced by reduced cozymase (reduced coenzyme I; DPN-H2); or by a mixture of DPN and fructosediphosphate.

The conversion of retinene1 to vitamin A1 is therefore a reduction in which two atoms of hydrogen are transferred to retinene1 from reduced cozymase. It is assumed that this reaction is catalyzed by an apoenzyme, retinene1 reductase, present in the rod outer limb. This process is coupled with a second system in the outer segment which reduces DPN, using hexosediphosphate or one of its derivatives as hydrogen donor. This action of DPN brings a member of the vitamin B complex, nicotinic acid amide, into an auxiliary position in the rhodopsin system.

In the isolated retina or in vitro systems the reduction of retinene1 proceeds irreversibly. Yet this reduction must be balanced by an oxidative process elsewhere in the rhodopsin cycle, since through rhodopsin as intermediate vitamin A1 regenerates retinene1.
THE ELECTRICAL PROPERTIES OF SYNTHETIC MEMBRANES
Authors: Albrink Wilhelm S. , Fuoss Raymond M.
Published: May 2004

By the addition of n-butyl bromide to a 1:19 copolymer of 4-vinylpyridine and styrene, water-insoluble, strong polyelectrolytes can be prepared. The addition of a hydrocarbon plasticizer permits the casting of flexible films in which large polycations are immobilized but in which bromide ions (or other small anions) are free to move. Electrical measurements on these membranes showed that they could be represented by a complex admittance: an electrolytic conductance in parallel with a pure A. C. impedance. The latter gives a circular arc when real component is plotted against imaginary. These synthetic membranes thus resemble in their electrical behavior that found by Cole for a variety of biological membranes.
TRANSPORT OF WATER FROM CONCENTRATED TO DILUTE SOLUTIONS IN CELLS OF NITELLA
Authors: Osterhout W. J. V.
Published: May 2004

The transport of water from concentrated to dilute solutions which occurs in the kidney and in a variety of living cells presents a problem of fundamental importance.

If the cell acts as an osmometer we may expect to bring about such transport by creating an inwardly directed osmotic drive which is higher in one part of the cell than in other regions of the same cell. The osmotic drive is defined as the difference between internal and external osmotic pressure.

Experiments with Nitella show that this expectation is justified. If water is placed at one end of the cell (A) and 0.4 M sucrose with an osmotic pressure of 11.2 atmospheres at the other end (B) water enters at A, passes along inside the cell, and escapes at B leaving behind at B the solutes which cannot pass out through the protoplasm. Hence the internal osmotic pressure becomes much higher at B than at A. When 0.4 M sucrose at B is replaced by 0.3 M sucrose with an osmotic pressure of 8.1 atmospheres we find that water enters at B, passes along inside the cell, and escapes at A so that water is transported from a concentrated to a dilute solution although the difference in osmotic pressure of the 2 solutions is more than 8 atmospheres. The solution at B thus becomes more concentrated.

It is evident that if metabolism produces a higher osmotic pressure and consequently a higher inwardly directed osmotic drive in one region of the cell as compared with other parts of the same cell water may be transferred from a concentrated to a dilute solution so that the former solution becomes still more concentrated.
PEPTIDASE ACTIVITIES OF EXTRACTS OF SALIVARY GLANDS OF DROSOPHILA MELANOGASTER
Authors: Patterson Elizabeth K. , Dackerman Marjorie E. , Schultz Jack
Published: May 2004

1. Peptide-splitting enzymes have been studied in buffered glycerine extracts of larval salivary glands of three stocks of Drosophila melanogaster.

2. The ultraviolet absorption spectrum of the glycerine extracts indicates the presence of a considerable amount of nucleic acid.

3. Alanylglycine (AG), leucylglycine (LG), leucylglycylglycine (LGG), glycylglycine (GG), and diglycylglycine (GGG) are split by the gland extracts in descending order of activity.

4. Of the various metals added, manganese was the only one found to give clear cut activation and that only with LGG as substrate. Cysteine inhibited the splitting of both AG and LG.

5. Comparison of the data with those published indicates the presence in the extracts in descending order of activity (at pH 7.6, 40°C.) of at least four enzymes: an AG-dipeptidase, an LG-dipeptidase, a leucineaminopeptidase, and possibly an aminopolypeptidase.

6. Optimum conditions for the measurement of the enzyme splitting AG were determined. The pH activity and kinetic data are typical for an AG-dipeptidase.

7. An enzyme (probably cathepsin II) splitting benzoyl-l-arginineamide (pH 5.0) with cysteine activation was observed to occur with very low activity in gland extracts.