bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal structure of truncated human βB1‐crystallin
Authors: van Montfort Rob L.M. , Bateman Orval A. , Lubsen Nicolette H. , Slingsby Christine 
Published: October 2003

AbstractCrystallins are long‐lived proteins packed inside eye lens fiber cells that are essential in maintaining the transparency and refractive power of the eye lens. Members of the two‐domain βγ‐crystallin family assemble into an array of oligomer sizes, forming intricate higher‐order networks in the lens cell. Here we describe the 1.4 Å resolution crystal structure of a truncated version of human βB1 that resembles an in vivo age‐related truncation. The structure shows that unlike its close homolog, βB2‐crystallin, the homodimer is not domain swapped, but its domains are paired intramolecularly, as in more distantly related monomeric γ‐crystallins. However, the four‐domain dimer resembles one half of the crystallographic bovine βB2 tetramer and is similar to the engineered circular permuted rat βB2. The crystal structure shows that the truncated βB1 dimer is extremely well suited to form higher‐order lattice interactions using its hydrophobic surface patches, linker regions, and sequence extensions.
Self‐assembly of single integral membrane proteins into soluble nanoscale phospholipid bilayers
Authors: Bayburt Timothy H. , Sligar Stephen G. 
Published: October 2003

AbstractOne of the biggest challenges in pharmaceutical research is obtaining integral membrane proteins in a functional, solubilized, and monodisperse state that provides a native‐like environment that maintains the spectrum of in vivo activities. Many of these integral membrane proteins are receptors, enzymes, or other macromolecular assemblies that are important drug targets. An example is the general class of proteins composed of seven‐transmembrane segments (7‐TM) as exemplified by the G‐protein–coupled receptors. In this article, we describe a simple system for self‐assembling bacteriorhodopsin, as a model protein containing 7‐TM helices, with phospholipids to form a nanometer‐scale soluble bilayer structure encircled by a 200 amino acid scaffold protein. The result is the single molecule incorporation of an integral membrane protein target into a soluble and monodisperse structure that allows the structural and functional tools of solution biochemistry to be applied.
The solution structure of the bacterial HSP70 chaperone protein domain DnaK(393–507) in complex with the peptide NRLLLTG
Authors: Stevens Shawn Y. , Cai Sheng , Pellecchia Maurizio , Zuiderweg Erik R.P. 
Published: October 2003

AbstractThe Hsp70 family of molecular chaperones participates in a number of cellular processes, including binding to nascent polypeptide chains and assistance in protein (re)folding and degradation. We present the solution structure of the substrate binding domain (residues 393–507) of the Escherichia coli Hsp70, DnaK, that is bound to the peptide NRLLLTG and compare it to the crystal structure of DnaK(389–607) bound to the same peptide. The construct discussed here does not contain the α‐helical domain that characterizes earlier published peptide‐bound structures of the Hsp70s. It is established that removing the α‐helical domain in its entirety does not affect the primary interactions or structure of the DnaK(393–507) in complex with the peptide NRLLLTG. In particular, the arch that protects the substrate‐binding cleft is also formed in the absence of the helical lid. 15N‐relaxation measurements show that the peptide‐bound form of DnaK(393–507) is relatively rigid. As compared to the peptide‐free state, the peptide‐bound state of the domain shows distinct, widespread, and contiguous differences in structure extending toward areas previously defined as important to the allosteric regulation of the Hsp70 chaperones.
Structure and stability of the ankyrin domain of the Drosophila Notch receptor
Authors: Zweifel Mark E. , Leahy Daniel J. , Hughson Frederick M. , Barrick Doug 
Published: October 2003

AbstractThe Notch receptor contains a conserved ankyrin repeat domain that is required for Notch‐mediated signal transduction. The ankyrin domain of Drosophila Notch contains six ankyrin sequence repeats previously identified as closely matching the ankyrin repeat consensus sequence, and a putative seventh C‐terminal sequence repeat that exhibits lower similarity to the consensus sequence. To better understand the role of the Notch ankyrin domain in Notch‐mediated signaling and to examine how structure is distributed among the seven ankyrin sequence repeats, we have determined the crystal structure of this domain to 2.0 Å resolution. The seventh, C‐terminal, ankyrin sequence repeat adopts a regular ankyrin fold, but the first, N‐terminal ankyrin repeat, which contains a 15‐residue insertion, appears to be largely disordered. The structure reveals a substantial interface between ankyrin polypeptides, showing a high degree of shape and charge complementarity, which may be related to homotypic interactions suggested from indirect studies. However, the Notch ankyrin domain remains largely monomeric in solution, demonstrating that this interface alone is not sufficient to promote tight association. Using the structure, we have classified reported mutations within the Notch ankyrin domain that are known to disrupt signaling into those that affect buried residues and those restricted to surface residues. We show that the buried substitutions greatly decrease protein stability, whereas the surface substitutions have only a marginal affect on stability. The surface substitutions are thus likely to interfere with Notch signaling by disrupting specific Notch‐effector interactions and map the sites of these interactions.
The geometry and efficacy of cation–π interactions in a diagonal position of a designed β‐hairpin
Authors: Tatko Chad D. , Waters Marcey L. 
Published: October 2003

AbstractCation–π interactions are common in proteins, but their contribution to the stability and specificity of protein structure has not been well established. In this study, we examined the impact of cation–π interactions in a diagonal position of a β‐hairpin peptide through comparison of the interaction of Phe or Trp with Lys or Arg. The diagonal interactions ranged from −0.20 to −0.48 kcal/mole. Our experimental values for the diagonal cation–π interactions are similar to those found in α‐helical studies. Upfield shifting of the Lys and Arg side chains indicates that the geometries of cation–π interactions adopted in the 12‐residue β‐hairpin are comparable to those found in protein structures. The Lys was found to interact through the polarized Cε, and the Arg is stacked against the aromatic ring of Phe or Trp. Folding of these peptides was found to be enthalpically favorable (ΔH° ∼ −3 kcal/mole) and entropically unfavorable (ΔS°∼ −8 cal mole−1 K−1).
Organization and dynamics of tryptophan residues in erythroid spectrin: Novel structural features of denatured spectrin revealed by the wavelength‐selective fluorescence approach
Authors: Chattopadhyay Amitabha , Rawat Satinder S. , Kelkar Devaki A. , Ray Sibnath , Chakrabarti Abhijit 
Published: October 2003

AbstractWe have investigated the organization and dynamics of the functionally important tryptophan residues of erythroid spectrin in native and denatured conditions utilizing the wavelength‐selective fluorescence approach. We observed a red edge excitation shift (REES) of 4 nm for the tryptophans in the case of spectrin in its native state. This indicates that tryptophans in spectrin are localized in a microenvironment of restricted mobility, and that the regions surrounding the spectrin tryptophans offer considerable restriction to the reorientational motion of the water dipoles around the excited state tryptophans. Interestingly, spectrin exhibits a REES of 3 nm even when denatured in 8 M urea. This represents the first report of a denatured protein displaying REES. Observation of REES in the denatured state implies that some of the structural and dynamic features of this microenvironment around the spectrin tryptophans are retained even when the protein is denatured. Fluorescence quenching data of denatured spectrin support this conclusion. In addition, we have deduced the organization and dynamics of the hydrophobic binding site of the polarity‐sensitive fluorescent probe PRODAN that binds erythroid spectrin with high affinity. When bound to spectrin, PRODAN exhibits a REES of 9 nm. Because PRODAN binds to a hydrophobic site in spectrin, such a result would directly imply that this region of spectrin offers considerable restriction to the reorientational motion of the solvent dipoles around the excited state fluorophore. The results of our study could provide vital insight into the role of tryptophans in the stability and folding of spectrin.
Modulating the binding properties of an anti‐17β‐estradiol antibody by systematic mutation combinations
Authors: Lamminmäki Urpo , Westerlund‐Karlsson Annette , Toivola Maria , Saviranta Petri 
Published: October 2003

AbstractThe anti‐17β‐estradiol antibody 57‐2 has been a subject for several protein engineering studies that have produced a number of mutants with improved binding properties. Here, we generated a set of 16 antibody 57‐2 variants by systematically combining mutations previously identified from phage display–derived improved antibody mutants. These mutations included three point mutations in the variable domain of the light‐chain and a heavy‐chain variant containing a four‐residue random insertion in complementarity determining region CDR‐H2. The antibody variants were expressed as Fab fragments, and they were characterized for affinity toward estradiol, for cross‐reactivity toward three related steroids, and for dissociation rate of the Fab/estradiol complex by using time‐resolved fluorescence based immunoassays. The double‐mutant cycle method was used to address the cooperativity effects between the mutations. The experimental data were correlated with structural information by using molecular modeling and visual analysis of the previously solved antibody 57‐2 crystal structures. These analyses provided information about the steroid‐binding mode of the antibody, the potential mechanisms of individual mutations, and their mutual interactions. Furthermore, several combinatorial mutants with improved affinity and specificity were obtained. The capacity of one of these mutants to detect estradiol concentrations at a clinically relevant range was proved by establishing a time‐resolved fluorescence based immunoassay.
Chemical modification of insulin in amyloid fibrils
Authors: Nilsson Melanie R. , Dobson Christopher M. 
Published: October 2003

AbstractWe have investigated the chemical modification of insulin under conditions that promote the conversion of the soluble protein into amyloid fibrils. The modifications that are incorporated into the fibrils include deamidation of Asn A21, Asn B3, and Gln B4. In order to prepare fibrils with minimal deamidation of these residues, the kinetics of aggregation were accelerated by seeding with aliquots of a solution containing preformed fibrils. The resulting fibrils were then reincubated to determine the extent to which chemical modification occurs in the fibril itself. The deamidation of Asn A21 in particular could be followed in detail. Deamidation of this residue in the fibrillar form of insulin was found to occur in only 52 ± 5% of molecules. This result indicates that there are at least two different packing environments of insulin molecules in the fibrils and suggests that the characterization of chemical modifications may be a useful probe of the environment of polypeptide chains within amyloid fibrils.
Peptide models of four possible insulin folding intermediates with two disulfides
Authors: Jia Xiao‐Yuan , Guo Zhan‐Yun , Wang Yao , Xu Ye , Duan Shun‐Shan , Feng You‐Min 
Published: October 2003

AbstractThe single‐chain insulin (PIP) can spontaneously fold into native structure through preferred kinetic intermediates. During refolding, pairing of the first disulfide A20–B19 is highly specific, whereas pairing of the second disulfide is likely random because two two‐disulfide intermediates have been trapped. To get more details of pairing property of the second disulfide, four model peptides of possible folding intermediates with two disulfides were prepared by protein engineering, and their properties were analyzed. The four model peptides were named [A20–B19, A7–B7]PIP, [A20–B19, A6–B7]PIP, [A20–B19, A6–A11]PIP, and [A20–B19, A7–A11]PIP according to their remaining disulfides. The four model peptides all adopt partially folded structure with moderate conformational differences. In redox buffer, the disulfides of the model peptides are more easily reduced than those of the wild‐type PIP. During in vitro refolding, the reduced model peptides share similar relative folding rates but different folding yields: The refolding efficiency of the reduced [A20–B19, A7–A11]PIP is about threefold lower than that of the other three peptides. The present results indicate that the folding intermediates corresponding to the present model peptides all adopt partially folded conformation, and can be formed during PIP refolding, but the chance of forming the intermediate with disulfide [A20–B19, A7–A11] is much lower than that of forming the other three intermediates.
Veneration and renovation at a small Norfolk priory: St. Leonard's, Norwich in the later middle ages*
Authors: Heale M. R. V. 
Published: October 2003

Abstract
Much remains obscure about the many small monasteries of late medieval England, and it is generally thought that they made little contribution to the religious life of the country. The large collection of accounts surviving from St. Leonard's priory, Norwich (a daughter house of the cathedral priory), however, presents an interesting picture of a priory sustained almost entirely by offerings to its image of St. Leonard. This cult continued to attract broad support throughout the later middle ages, with its income reaching a peak at over forty pounds per year in the mid fifteenth century. Almost the entirety of this windfall was set aside for a systematic renovation of the monastery, which can be chronicled in some detail. Although the cult was on the wane by 1500, the importance of the priory for the popular religion of the region emerges clearly.
Elizabeth I and the verdicts of history*
Authors: Collinson Patrick 
Published: October 2003

Abstract
Archbishop Matthew Parker feared that Elizabeth would be ‘strangely chronicled’. From her death to the screening of the film ‘Elizabeth’, the life of ‘Gloriana’ has been a subject for all kinds of imaginative fiction. History, too, has traded as much in myth as fact. Elizabeth's first historian, William Camden, was not responsible for the myth, although his translators were. The nineteenth century invented a ‘whiggish’ Elizabeth who identified herself with the destiny of her people, although the leading Tudor historian, A. J. Froude, was not a fan. Post-J. E. Neale and A. L. Rowse, Froude's critical interrogation of the reign has been revived in the latest Elizabethan historiography.
Patriarchs and republicans: eighteenth-century Virginian planters and classical politics
Authors: Lago Enrico Dal 
Published: October 2003

AbstractThis article argues that the metaphor of George Washington as Father of his Country– or Pater Patriae– must be seen in the context of the culture of the eighteenth-century Virginian planter élite. Classical education and English commonwealthmen's writings had given most planters familiarity with Roman republican figures such as Cicero, who first bore the title of Pater Patriae, and had prompted them to consider independence and disinterestedness for the sake of public good as the most important signs of virtue in the optimal republican citizen. At the same time, patriarchalism – the prominent ethos among Virginian planters – dictated that the representatives of the upper classes ought to display their virtue through an attitude of benevolence towards the lower strata of society, and especially towards the slaves.
Authority, honour and the Strachey family, 1817–1974*
Authors: Lubenow William C. 
Published: October 2003

Abstract
The Strachey family, like other professional families in the nineteenth and twentieth centuries, transformed concepts of honour and authority. Rather than rooting such concepts in the values of birth and wealth, the Stracheys realized and utilized the ironic possibilities in the conventions of their time to reshape their understanding of the ways that they fit into the world. The Stracheys were a literary family. In things Indian and imperial, in things French, and in psychoanalysis they negotiated the discontinuities and uncertainties of the modern world in their drive for power, place, meaning, intimacy and a different kind of authority.
Reframing disease: changing perceptions of tuberculosis in England and Wales, 1938–70
Authors: Hardy Anne 
Published: October 2003

Abstract
Perceptions of the character of tuberculosis changed between 1940 and 1970 following the application of new medical technologies and investigative methods in the diagnosis and tracing of the disease. This article examines how that change occurred through a survey of the epidemiological literature, principally relevant journals. It concludes that the new techniques replaced the old romanticized image of tuberculosis as a disease of youth with one centred on children and the old. There has been little research on tuberculosis in Britain since 1940, and none that explores the significant change in image which the disease has undergone since then. This article is a beginning.
Patterns of Immigrant Occupational Attainment in a Longitudinal Survey
Authors: Chiswick Barry R. , Lee Yew Liang , Miller Paul W. 
Published: October 2003

AbstractThis paper uses data from the Longitudinal Survey of Immigrants to Australia to examine the empirical relevance of a model of immigrant occupational mobility. Consistent with the model, there is a U‐shaped pattern of occupational change from the pre‐immigration occupation through to the occupation held after three‐and‐a‐half years in Australia. The U is shallower for immigrants from countries similar to Australia than it is for immigrants from countries that differ more in language, occupational requirements, and labour market structure. The U‐shaped pattern is deeper for immigrants who are refugees than for family migrants and is the least deep for economic migrants.
Attitudes of Botswana Citizens toward Immigrants: Signs of Xenophobia?
Authors: Campbell Eugene K. 
Published: October 2003

AbstractThis study is borne out of observations over the past decade that citizens of Botswana were increasingly feeling resentful of labour immigrants in the country. A survey questionnaire was administered to a sample of 781 male and female Batswana (citizens of Botswana) in three urban centres in Botswana. The purpose was to obtain opinions of Batswana about immigrants. The paper begins by examining the meaning of xenophobia. The results indicate that Batswana are xenophobic; it appears that this attitude is influenced by a combination of nationalism and economic factors. There is a strong desire to preserve the “fruits” of economic prosperity for citizens alone. Europeans and North Americans are most preferred in terms of being accepted as part of the Botswana society and among those who may apply to become citizens of Botswana. The second most preferred are Africans. Asians, especially Indians, are the least preferred. Indeed, Botswana citizens of Indian descent are viewed with considerable suspicion and dislike by other citizens of the country. Primarily for this reason, Asians seem to be the worst victims of xenophobia in Botswana. Short‐ and specific‐term residences by immigrants are preferred over permanent residence. Some citizens are prepared to take every possible action to discourage immigrants from staying in the country; few would employ violent methods to achieve this goal.
Family Change and Economic Well‐being in Canada: The Case of Recent Immigrant Families with Children
Authors: Liu Jianye , Kerr Don 
Published: October 2003

AbstractThis paper examines the relationship between family change and economic well‐being among recent immigrant families with children to Canada during the 1977 to 1997 period. Whereas the average income to needs ratio of all Canadian families with children is up modestly over this period, this study documents a substantial decline in the average level of economic well‐being of recent immigrants. In this context, this study draws attention to the relevance of not only structural explanations that emphasize the role of labour markets and/or government policy in shaping the economic conditions of immigrants, but also the potential impact of shifts in the living arrangements and family structure of immigrants. More specifically, an increased incidence of lone parenthood has had a net negative impact on the economic well‐being of immigrants, albeit not to the same extent as among non‐immigrants in Canada. Yet, other changes have had a slight positive impact, including an ongoing decline in the average number of children per family, an upward shift in the age distribution of parents, and a slight increase in the tendency of immigrants to co‐reside with family members beyond the immediate nuclear family.
Economic Integration among Children of Israeli Immigrants in the United States
Authors: Cohen Yinon , Haberfeld Yitchak 
Published: October 2003

AbstractThe paper analyses the economic assimilation of first, 1.5, and second generation Israeli Jewish immigrants in the United States. The empirical analyses are based on the 1990 public use sample (PUMS) that enables the identification of adult children of Jewish Israeli immigrants. The analyses show that all groups of Jewish Israeli immigrants in the United States are doing very well relative to a benchmark of native‐born Americans. The comparisons also indicate that children of immigrants — both men and women — are even more successful economically than the immigrants themselves. The economic success of Israeli immigrants and their offspring in the United States is due not only to their high level of education, but also to unmeasured traits that help them earn more than demographically comparable natives.
State and Corporate Cash Management: A Comparison
Authors: Mattson Kyle , Hackbart Merl , Ramsey James R. 
Published: October 2003

Public and private sector portfolio managers pursue similar goals even though they perform their portfolio management responsibilities in significantly different environments. This article compares and contrasts corporate cash management with state government practices. The comparison and analyses are based on data drawn from a survey of state government portfolio managers and an earlier study which reviewed corporate cash management practice.The comparison and analyses consider investment objectives, permissible assets, assets held, and asset holding period, among other factors. The results suggest that portfolio management practices are quite similar even though the cash management environment is significantly different.