bluuebunny/crossref_metadata_2025_split huggingface dataset:
CORRELATIONS BETWEEN AMINO ACID SEQUENCE AND CONFORMATTON OF IMMUNOGLOBULIN LIGHT CHAINS
Authors: Welscher H. D. 
Published: August 2010

The significance of nonpolar and of charged residues for the corrformation of light chains is discussed, based on the amino acid sequence of 15 light chains and on the amino acid composition of light chains from I1 species.The nonpolar residues contribute to the conformational stability by hydrophobic interactions with an average hydrophobicity of about 1000 caliresictue; this value is essentially independent of isotypic and ictiotypic sequence variability, and is similar to that for other globular proteins. While ihe total h.vdrophobicity of many globular proteins containing no SS bridges compensates afniost exclusively for their cotiforma‐ tional entropy, a significant discrepancy is observed in the case of light chains. This rnav rejlect the loss of conformational entropy clue to ihe two SS bridges forming independent covalent loops. The ioni7cd residue;, give a fractional charge close to 0.20 unitsiresirlue. This relatively low value, together with the relatively high average hydrophobicity, cxplains qualitatively many of the a5sociation and thermal properties of light chains. Variable and constant regions of light chains exhibit nearly identical average hydrophobicities and fracfional charges, suggesting that the molecules are folded into two distinct structural subunits of compact conformation.Some preliirrirrary results on heavy chains are also considered: The fructional charge of the Fdjragments are much lowcr than that of the Fc fragments. This may fucilitate the intimate contact oj the light chain with the former fragment in the intact antibody molecule.
AMINO ACID COMPOSITIONS and N‐TERMINAL AMINO ACIDS OF ALL THE TRYPTIC PEPTIDES FROM THE α and β POLYPEPTIDE CHAINS OF ADULT HEMOGLOBIN OF THE RHESUS MONKEY (Macaca mulatto)
Authors: Matsuda Genji , Maita Tetsuo , Take Hiroshi 
Published: August 2010

Globin prepared from adult hemoglobin of the rhesus monkey was separated into α and β polypeptide chains by the countercurrent distribution method. The α and β polypeptide chains were digested with trypsin. All the tryptic peptides were isolated and purified by column and paper chromatography. The amino acid compositions and the N‐terminal amino acid of these tryptic peptides were analyzed. According to the results thus obtained, the α and β polypeptide chains of adult hemoglobin of the rhesus monkey are respectively composed of 141 and 146 amino acid residues just as those of human hemoglobin. However, it is presumed that there exist at least four amino acid substitutions in the a polypeptide chain and eight in the β polypeptide chain.
STUDIES ON THE CONFORMATION OF AMINO ACIDS*
Authors: Ponnuswamy P. K. , Sasisekharan V. 
Published: August 2010

In this paper, the results of the potential energy calculations on the conformations of some amino acids are given. The non‐bonded, electrostatic, and torsional contributions to the total energy of the molecule were calculated using appropriate functions and their role in predicting the conformation of amino acids is discussed. It is shown that electrostatic interaction between the amino group and the carboxyl group is mainly responsible for the plane of the carboxyl group to be coplanar with the plane through N, Cα, and C1atoms. It is also shown that the presence of a γ‐atom in position II necessiates a large deviation from the coplanarity between the carboxyl plane and the N, Cα, C plane. The results indicate that the backbone conformations of all the amino acids are nearly the same and could be shown to be the same as those of glycine and alanine. Also, the theoretically predicted conformations about the Cα‐Cβ bond in aminobutyric acid could explain the observed γ‐atom positions in all the amino acids.
THE PRIMARY STRUCTURE OF THE α and β POLYPEPTIDE CHAINS OF ADULT HEMOGLOBIN OF THE RHESUS MONKEY (Macaca mulatto)
Authors: Matsuda Genji , Maita Tktsuo , Ota Hisahiro , Takei Hiroshi 
Published: August 2010

Countercurrent distribution separated rhesus monkey hemoglobin into α and β polypeptide chains, which were respectively oxidized with performic acid, dissolved in 8 M urea to be denatured at 60° for 45 min, and then digested with pepsin at 37° for 2 hours. Peptic peptides thus obtained from each polypeptide chain were isolated and purified by column‐ and by paper chromatography, and the amino acid composition of each peptide was analyzed. Sequence analysis was carried out by using PTC and DNP methods, if necessary. From the results thus obtained, the present authors established the primary structure of rhesus monkey hemoglobin, taking account of the amino acid sequence in all the tryptic peptides from the α and β polypeptide chains previously reported.
ON THE CONFORMATION OF HISTONES: CD STUDIES ON THE LYSINE‐ and SERINE‐RICH FRACTIONS FROM AVIAN ERYTHROCYTES
Authors: Tamburro A. M. , Scatturin A. , Vidau G. 
Published: August 2010

Circular dichroism studies of avian erythrocytes lysine‐rich and serine‐rich histone fractions are reported. Both histones are essentially disordered in aqueous solutions. In aqueous methanol the lysine‐rich fraction undergoes a coil‐to‐helix transition. The same property is enhanced in the serine‐rich histone, and at high methanol percentage the fraction is partially in β form.
STUDIES ON SUCCTNYLATED and MALEYLATED ATP: CREATINE PHOSPHOTRANSFERASE
Authors: Grant‐Greene M. C. , Friedbf.rg F. 
Published: August 2010

After treatment of ATP creatine transphosphoryla.se with maleic or succinic anhydride, the enzyme was purified using Sephadex G‐25 and the number of s‐lysine groups that reacted determined by utilization of radioactive maleic anhydride, U. V. spectroscopy, titration of succinic acid liberated upon hydrolysis, and by dinitrophenylation. Before exposure to hydroxylamine, about J 20 moles anhydride were bound per mole of protein; and after exposure, about 68 moles remained ligated. Low speed sedimentation equilibrium experiments showed that maleylation induced formation of subunits of molecular weight half that of the original molecule. After digestion of the maleylated protein with trypsin, the resulting peptides were separated on a Dowex column, followed by high voltage electrophoresis and paper chromatography. Twenty‐two spots were obtained, all of which were positive when sprayed with Sakaguchi reagent.
STUDIES ON THE CONFORMATION OF AMINO ACIDS
Authors: Balasubramanian R. , Lakshminarayanan A. V. , Sabesan M. N. , Tegoni G. , Venkatesan K. , Ramachandran G. N. 
Published: August 2010

The paper deals with an analysis of the available crystal structure data related to proline compounds so as to obtain information about bond lengths, bond angles, and the conformation of the pyrrolidine ring. The interesting results are: 1. The atoms Cβ, Cα, N, and Cß are nearly coplanar, with the torsion angle 0 about the Cα ‐ N bond varying from about ‐15° to ‐15°. The Cγ atom is displaced from this plane, either up or down, so that the ring exists in one of the two puckered conformations, designated A and B. Conformation A is characterized by negative and may be termed Cγ‐exo when referred to the displacement of the carbonyl carbon C. Conformation B has positive xl and is Cγ‐endo; Cγ‐exo is slightly preferred over C‐endo, although both conformations occur simultaneously in some crystal structures with partial probabilities. In the other structures, the non‐occurring position for Cy is found to be disallowed by intermolecular contacts. The proline conformations observed correspond to the‘envelope’type of conformation of the cyclopentane ring. In peptides, the three bonds at N are nearly coplanar, and the torsion about N‐ Cα bond is nearly ‐ 60°. 2. The observed ranges of (x1, x2, x3, x4) are (0 to –30°, 15 to 50°, –15 to ‐ ‐30°, 5 to 25°) for conformation A and (20 to 350, ‐30 to ‐ 400, 20 to 35°, 5 to ‐20°) for conformation B; for θ and φ the ranges are ‐15° to ‐15°, ‐45 to ‐75°. The bond lengths and bond angles are not influenced by the conformation of the ring, unlike ribose.
HUMAN CERULOPLASMIN AS A POLYMORPHIC GLYCOPROTEIN
Authors: Rydén Lars 
Published: August 2010

Reduced and cyanoethylated human ceruloplasmin form I was freed of sialic acid and digested by trypsin. A glycopeptide fraction isolated by gel filtration was separated into three carbohydrate‐containing fractions by ion exchange chromatography on Dowex I. Each of these was further separated by column electrophoresis to yield a unique glycopeptide. With a stoichiometry of two chains per mole, these peptides account reasonably well for all the carbohydrate in the molecule. In a corresponding preparation from ceruloplasmin form II with smaller carbohydrate content, two of the glycopeptides were, present in greatly reduced amounts. The three glycopeptides were obtained in a pure state from sialic acid‐containing ceruloplasmin form I by gel filtration, ion exchange chromatography, and column electrophoresis. Two different kinds of oligosaccharide chains were found attached to the purified peptides. The first contained 6 hexose, 5 glucosamine, 2 sialic acid, and 0.5 fucose residues; the other about 9 hexose, 8 glucosamine, 4 sialic acid, and 0.5 fucose residues. According to the composition of the protein, the larger chain accounts only for a small part of the carbohydrate content. On the basis of the results, it is proposed that human ceruloplasmin has six carbohydrate chains, three on each of two identical or nearly identical halves of the molecule. The carbohydrate chains are found in two different degrees of completion. Form II of the protein lacks 2–3 of these chains, having two particular sites partly unsubstituted.
ISOLATION OF A FROG HEMOGLOBIN (Rana esculenta)
Authors: Chauvet Jean‐Pierre , Acher Roger 
Published: August 2010

Hemoglobin from adult frogs (Rana esculenta) was purified by fractionated precipitation with ammonium sulfate and chromatography on carboxymethyl‐Sephadex C 50. The chromatography resolved hemoglobin into two components, Hemoglobins I and II, which have apparently similar amino acid compositions but different electro‐phoretic mobilities. Reduced globin prepared from Hemoglobin II was separated into a and p polypeptide chains by counter‐current distribution. The purity of each chain was estimated by starch gel electrophoresis. The amino acid compositions of α and β chains were determined. The N‐terminal sequences were established by using the dinitrofluorohenzene andphe‐nylisothiocyanate techniques as well as peptic hydrolysis; the C‐terminal sequences were determined with carboxypeptidases A and B, hydrazinolysis, and tryptic hydrolysis.
ISOLATION AND CHARACTERIZATION OF SOME FRAGMENTS OBTAINED AFTER PEPTIC DIGESTION OF BOVINE SERUM ALBUMIN
Authors: Braam W. G. M. , Harmsen B. J. M. , Walters J. A. L. I. , van Os G. A. J. 
Published: August 2010

Bovine serum albumin was hydrolysed by pepsin at pH 3.7. Ten well‐defined fragments were found, as was shown by electrophoresis on polyacrylamide gels at pH 3.0 in the presence of 6 M urea. Three of the fragments could be isolated by precipitation with trichloroacetic acid followed by ion exchange chromatography. The procedure is suited to obtain large quantities in a simple and reproducible way. The fragments were identified by polyacrylamide gel electrophoresis, terminal amino acid determination, and amino acid analysis. The largest of the three fragments appeared to be composed of the two other fragments and is probably placed C‐terminal in albumin. Some other properties of the largest fragment were also determined, e.g., the α‐helix content and the number of titratable residues.
INTERNAL SYMMETRIES OF THE HISTONE F 2b MOLECULE AND SEVERAL OTHER POLYPEPTIDE SEQUENCES
Authors: Bauer Klausdieter 
Published: August 2010

A thorough analysis of the histone F 2b sequence for internal homologies revealed the occurrence of internal symmetries of this molecule distributed among 6 different regions, 2 of which are homologous to histone IV (F 2al). A preliminary search for intramolecular symmetries in other proteins showed patterns of this type in 8 more cases, including kallidin I, ACTH, glucagon, insulin A‐chain, ribonuclease, phospholipase A, cytochrome b3, and the coat protein from the f 2 phage. The findings on immunoglobulins and ferredoxin, reported in the literature, add these two proteins to the same list. The general importance of the mechanism responsible, which leads to the development of base symmetries in animal, plant, and viral proteins, is discussed in detail. Histones F 2b and F 2al (IV), and several clupeines were, moreover, demonstrated to share a common ancestor sequence, which developed by both serial and symmetrical duplication to form part of present‐day basic nuclear proteins.
AMINO ACID COMPOSITIONS OF THE SOLUBLE TRYPTIC PEPTIDES AND CHYMOTRYPTIC PEPTIDES FROM THE α POLYPEPTIDE CHAIN OF All COMPONENT OF CHICKEN HEMOGLOBIN
Authors: Matsuda Genji , Takei Hiroshi , Wu Ku Chayu , Shiozawa Tsuneo 
Published: August 2010

All component prepared from adult chicken hemoglobin was separated into α and β polypeptide chains by column chromatography. Of the two chains, the a polypeptide chain was digested with trypsin. The soluble tryptic peptides thus obtained were isolated and purified by column chromatography and paper chromatography. On the other hand, the a polypeptic chain in AH component was digested with chymotrypsin. The chymotryptic peptides thus obtained were isolated and purified by column chromatography and paper chromatography the same way as in the case of tryptic peptides. The amino acid compositions of these tryptic and chymotryptic peptides were analyzed.
Survival after transfusion in the Netherlands
Authors: Borkent‐Raven B. A. , Janssen M. P. , van der Poel C. L. , Schaasberg W. P. , Bonsel G. J. , van Hout B. A. 
Published: August 2010

Background  Cost‐effectiveness analyses of blood safety interventions require estimates of the life expectancy after blood product transfusion. These are best derived from survival after blood transfusion, per age group and blood component type.Study design and methods  In the PROTON (PROfiles of TransfusiON recipients) study transfusion recipient data was collected from a hospital sample covering 28% of the total blood use between 1996 and 2006 in the Netherlands. The dataset includes date of transfusion, blood component type transfused and recipient identification details. PROTON data were individually matched to mortality data of the Netherlands. Survival after first transfusion and after any transfusion was calculated, per blood component type and age group. PROTON mortality rates were compared to mortality rates in the general population. The results were used to estimate survival beyond the study period and to estimate life expectancy after transfusion.Results  Of all 2 405 012 blood product transfusions in the PROTON dataset, 92% was matched to the national Dutch Municipal Population Register, which registers all deaths. After 1 year, survival after any transfusion was 65·4%, 70·4% and 53·9% for RBC, FFP and PLT respectively. After 5 years, this was 46·6%, 58·8% and 39·3% for RBC, FFP and PLT, respectively. Ten years after transfusion, mortality rates of recipients are still elevated in comparison with the general population.Conclusion  Mortality rates of transfusion recipients are higher than those of the general population, but the increase diminishes over time. The mortality rates found for the Netherlands are lower than those found in comparable studies for other countries.
The Effects of Relaxed and Reversed Selection by Predators on the Antipredator Behavior of the Threespine Stickleback, Gasterosteus aculeatus
Authors: Messler Alexis , Wund Matthew A. , Baker John A. , Foster Susan A. 
Published: August 2010

AbstractIsolation from predators can lead to the reduction or loss of ancestral behavioral defenses in prey, but does not always do so. Predators introduced to populations that have experienced relaxed selection from some ancestral predators can favor the evolution of antipredator behavior that has been lost. We examined these possibilities by eliciting antipredator behavior in three populations of threespine stickleback fish, Gasterosteus aculeatus: an oceanic population thought to resemble the ancestral form, and two populations historically (up to 20 000 yr) devoid of piscine predators (relaxed selection), one of which has been stocked with salmonids for nearly 25 yr (reversed selection). We used three kinds of predator models: a sculpin (ambush predator), a rainbow trout (chasing predator), and an overhead silhouette of an arctic tern. Stickleback reacted differently to the three models, indicating that they distinguished among them. Individuals from all populations responded similarly to the tern model. The ancestral population showed the weakest response to the sculpin model despite being the only population that encounters these predators naturally. Stickleback from the trout‐free population displayed slightly reduced responses to the trout model, and recovery times like those in the ancestral population providing only weak evidence for loss of the ancestral antipredator repertoire. Fish from the reverse‐selected population exhibited fascinating, elevated responses to both the trout and sculpin models relative to the other two populations. These findings offer initial evidence of (1) a partial alteration of the ancestral behavioral repertoire during a long period of relaxed selection from piscine predators, and (2) rapid acquisition of extreme responses to piscine predators under reverse selection.
Display of an Inedible Prop as a Signal of Aggression? Adaptive Significance of Leaf‐Display by the Turquoise‐Browed Motmot, Eumomota superciliosa
Authors: Murphy Troy G. 
Published: August 2010

AbstractThe incorporation of an inedible object (prop) into a behavioral display is rare among birds. Only four avian taxa have been reported to display with a prop, and in all studied species, prop use has been found to play a role in mate acquisition. However, little is known about the context and adaptive significance of prop use by the motmots. Both male and female motmots perform a leaf‐display, whereby a leaf is held horizontally in the tip of the bill for an extended period. I collected observational data on leaf‐display by the turquoise‐browed motmots (Eumomota superciliosa) to investigate the potential role of this display as a mate‐choice or agonistic signal. Observations of 61 leaf‐displays by 27 individuals indicate that males and females are similarly likely to perform the leaf‐display, that the leaf‐display is performed throughout the long‐breeding season, and that the display is performed by both paired and unpaired birds. These observations suggest that the leaf‐display does not play a role in mate‐attraction. However, the leaf‐display was often performed in association with a chase or fight with a same‐sex individual, and the display was sometimes performed in conjunction with an agonistic display at nest sites, suggesting that the leaf‐display may function in both sexes as a signal of aggressive intent or as a signal of status.
Contextual Flexibility: Reassessing the Effects of Prey Size and Status on Prey Restraint Behaviour of Macrostomate Snakes
Authors: Mehta Rita S. , Burghardt Gordon M. 
Published: August 2010

AbstractContextual flexibility in prey restraint behaviour has been documented in advanced snakes (Colubroidea), but the degree of flexibility for earlier snake lineages has been largely unstudied. We document the prey restraint behaviour of five snake species belonging to three early macrostomate lineages: Loxocemidae, Erycinae and Boidae. Species from these lineages were chosen for this study because they utilize similar prey resources but exhibit different ecological habits that may have important consequences on prey restraint behaviour. Snakes (n = 27) were studied in a systematic experimental design assessing the effects of mouse size (small and large) and status (live and dead) across a total of 216 feeding trials. Loxocemus and Erycine snakes were highly flexible in their prey restraint behaviour patterns and these varied across prey category. Individuals of Boa constrictor exhibited very little contextual flexibility in feeding behaviour, confirming earlier reports. Flexibility in prey restraint behaviour corresponded with loop application pattern, whether the snake bent laterally or ventrally when forming a loop around prey. Our study is the first to show that early macrostomate snakes exhibit flexible prey restraint behaviours. Thus, our results suggest that flexibility in predatory behaviour may be more widespread across snake taxa than previously thought and we offer hypotheses for the observed interspecific differences in snake feeding behaviour.
Pigeon Homing: The Navigational Map Developed in Adulthood is Based on Olfactory Information
Authors: Ioalè Paolo , Savini Maria , Gagliardo Anna 
Published: August 2010

AbstractHoming pigeons raised in a shielded aviary and kept confined until the day of the test releases are not able to navigate even if, once adult, the screens are removed and the birds are exposed to natural winds for a sufficiently long period for map learning. However, pigeons raised in the same condition but, once adult, allowed to perform spontaneous flights around the loft are able to develop navigational abilities which, however, never reach the level of controls. In the present study, we show that the navigational map learned by the adult birds, which had the possibility to perform spontaneous flights, is based on olfactory information.
Remission of the Free‐branching Pattern of Euphorbia pulcherrima by Tetracycline Treatment
Authors: Bradel B. G. , Preil W. , Jeske H. 
Published: August 2010

AbstractAntibiotic‐mediated suppression of the free‐branching (FB) pattern of commercially available poinsettia cv.‘Angelika’ (Euphorbia pulcherrima) supports recent results that the causative agent responsible for branching is a phytoplasma. Scions of phytoplasma containing FB plants were treated with tetracycline at 100–1000 parts per million (p.p.m.). The plants grew monopodially and phytoplasmas were not detected for several weeks after grafting onto restricted‐branching (RB) poinsettia. After prolonged growth without antibiotic treatment, phytoplasmas reappeared in most plants which became FB again and one plant escaped from phytoplasma infection. In some poinsettia plants, the FB morphotype developed before phytoplasmas were detected by polymerase chain reaction. For the cultivar ‘Angelika’ the same poinsettia branch‐inducing (PoiBI) phytoplasma (X‐disease group; subgroup H) was detected by restriction fragment length polymorphism analysis of 16S rDNA as previously found in the United States (Lee et al., Int. J. Syst. Bacteriol. 48, 1153–1169, 1998).