scholarly journals The V-region sequence of the H chain from a third rabbit anti-pneumococcal antibody

1976 ◽  
Vol 157 (2) ◽  
pp. 449-459 ◽  
Author(s):  
J C Jaton

The amino acid sequence of the V (variable) region of the heavy (H) chain of rabbit antibody BS-1, raised against type III pneumococcal vaccine, is reported. Together with the sequence data of the V region of the light (L) chain previously determined [Jaton (1974a) Biochem. J. 141, 1-13], the present work completes the analysis of the V domain of the homogeneous antibody BS-1. The V domains (VL + VH regions) of this antibody are compared with those of two other anti-(type III) pneumococcal antibodies BS-5 and K-25 [Jaton (1975) Biochem. J. 147, 235-247]. Except for the second hypervariable section of the L chains, these antibodies have very different sequences in the hypervariable segments of the V domains. Within the third hypervariable region of the H chain, each antibody has a different length: BS-1 is three amino acids shorter than K-25 and two amino acids shorter than BS-5. When the sequences in that section are aligned for maximal homology, only two residues, glycine-97 and leucine-101, are common to the three antibodies. On the basis of the amino acid sequences of these three anti-pneumococcal antibodies, the results do not support the concept of a simple correlation between primary structure in the hypervariable sections (known to determine the shape of the combining site) and antigen-binding specificity.

1974 ◽  
Vol 143 (3) ◽  
pp. 723-732 ◽  
Author(s):  
Jean-Claude Jaton

The amino acid sequence between residues 70 and 116 of the V (variable) region of the H (heavy) chain derived from rabbit antibody BS-5, specific for type III pneumococcal polysaccharide, was determined. The sequence of this section of the H chain which includes the hypervariable residues 94 to about 112 was unique, although minor variant sequences present in the H chain preparation would not have been detected by the techniques used in this work. Taken together with the known sequences of the N-terminal 69 residues of H chain BS-5 (Jaton & Braun, 1972) and of the V region of the light chain (Jaton, 1974b), the data establish the complete sequence of the V domain of a rabbit immunoglobulin G. The V region of H chain BS-5 is compared with the basic sequences of the three human V region subgroups known to date, with one mouse H chain, and with guinea-pig pooled H chains. Even though chains from guinea pig and mouse clearly belong to the subgroup III of variability (VHIII), rabbit H chain BS-5 (allotypic variant a1) appears more closely related to the subgroup VHII than to the subgroups VHIII or VHI. The homology between VL and VH regions of antibody BS-5 (28%) is not greater than that observed between the VH region of antibody BS-5 and the VL regions of different rabbit antibodies.


1975 ◽  
Vol 147 (2) ◽  
pp. 235-247 ◽  
Author(s):  
J C Jaton

The amino acid sequences of the V (variable) regions of the H (heavy) and L (light) chains derived from rabbit antibody K-25, specific for type III pneumococci, were determined; this is the second homogeneous rabbit antibody besides antibody BS-5 whose complete sequence of the V domain has been established (Jaton, 1974d). The V regions of L chains BS-5 and K-25 (both of allotype b4) differ from each other by 19 amino acid residues; 11 of these 19 substitutions are located within the three hypervariable sections of the V region. On the basis of seven amino acid differences within the N-terminal 28 positions, it is suggested that L chain K-25 belongs to a different subgroup of rabbit K chains and L chain BS-5. H chain K-25 (allotype a2) differs from another H chain of the same allotype by one amino acid substitution within the N-terminal 70 positions in addition to interchanges occurring in the first two hypervariable sections. H chain K-25 was compared with H chain BS-5 (allotype a1) and with the known V-region rabbit sequences. Allotype-related differences between a1, a2 and a3 chains appear to occur within the N-terminal 16 positions and possibly in scattered positions throughout the V-region. In the hypervariable positions, variability between the two antibodies is remarkably more pronounced within the third hypervariable section of both H and L chains than within the first two.


2006 ◽  
Vol 72 (7) ◽  
pp. 4653-4662 ◽  
Author(s):  
Dong Xu ◽  
Jean-Charles Côté

ABSTRACT We set out to analyze the sequence diversity of the Bacillus thuringiensis flagellin (H antigen [Hag]) protein and compare it with H serotype diversity. Some other Bacillus cereus sensu lato species and strains were added for comparison. The internal sequences of the flagellin (hag) alleles from 80 Bacillus thuringiensis strains and 16 strains from the B. cereus sensu lato group were amplified and cloned, and their nucleotide sequences were determined and translated into amino acids. The flagellin allele nucleotide sequences for 10 additional strains were retrieved from GenBank for a total of 106 Bacillus species and strains used in this study. These included 82 B. thuringiensis strains from 67 H serotypes, 5 B. cereus strains, 3 Bacillus anthracis strains, 3 Bacillus mycoides strains, 11 Bacillus weihenstephanensis strains, 1 Bacillus halodurans strain, and 1 Bacillus subtilis strain. The first 111 and the last 66 amino acids were conserved. They were referred to as the C1 and C2 regions, respectively. The central region, however, was highly variable and is referred to as the V region. Two bootstrapped neighbor-joining trees were generated: a first one from the alignment of the translated amino acid sequences of the amplified internal sequences of the hag alleles and a second one from the alignment of the V region amino acid sequences, respectively. Of the eight clusters revealed in the tree inferred from the entire C1-V-C2 region amino acid sequences, seven were present in corresponding clusters in the tree inferred from the V region amino acid sequences. With regard to B. thuringiensis, in most cases, different serovars had different flagellin amino acid sequences, as might have been expected. Surprisingly, however, some different B. thuringiensis serovars shared identical flagellin amino acid sequences. Likewise, serovars from the same H serotypes were most often found clustered together, with exceptions. Indeed, some serovars from the same H serotype carried flagellins with sufficiently different amino acid sequences as to be located on distant clusters. Species-wise, B. halodurans, B. subtilis, and B. anthracis formed specific branches, whereas the other four species, all in the B. cereus sensu lato group, B. mycoides, B. weihenstephanensis, B. cereus, and B. thuringiensis, did not form four specific clusters as might have been expected. Rather, strains from any of these four species were placed side by side with strains from the other species. In the B. cereus sensu lato group, B. anthracis excepted, the distribution of strains was not species specific.


1980 ◽  
Vol 151 (5) ◽  
pp. 1059-1070 ◽  
Author(s):  
B Clevinger ◽  
J Schilling ◽  
L Hood ◽  
J M Davie

For the first time V-region amino acid sequence differences have been correlated with the expression of cross-reactive and individual idiotypes through an analysis of 12 dextran-binding proteins. This correlation has been possible because of the apparent sequence identity of the corresponding lambda chains. Expression of a cross-reactive idiotype was localized to two residues and/or a carbohydrate in the second hypervariable region of the heavy chain. Two individual idiotypes correlate with the two amino acids within the third hypervariable region that comprises the D segment of the dextran-binding proteins. These results demonstrate that idiotype reagents can recognize two amino acid differences within V and D segments of classical variable regions. In anti-dextran antibodies, cross-reactive idiotypes involve V-region determinants, whereas individual idiotype determinants correlate with D-segment variation.


1980 ◽  
Vol 36 (2) ◽  
pp. 181-197 ◽  
Author(s):  
Tomoko Ohta

SUMMARYLinkage disequilibrium between segregating amino acid sites in repeated genes which form a multigene family was investigated by using the population genetics theory. The degree of non-random association of amino acids is measured by the disequilibrium coefficient which is determined by the balance among various forces; unequal and equal crossing-over, mutation, random genetic drift and recombination which takes place between the two sites in question. Another measure of disequilibrium, ‘standardized identity excess’, represents excess probability of simultaneous identity at the two sites over that expected from random association of amino acids. Sequence data of variable region of immunoglobulins provide most interesting example of multigene family to apply the theory. Statistical analyses on identity excess for various groups and subgroups of variable region sequences of immunoglobulins suggest that a multigene family such as human κ or mouse κ gene family consists of several subfamilies between which recombination is limited. The analyses also indicate that the recombination may take place between any gene members in one subfamily.


1974 ◽  
Vol 141 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Jean-Claude Jaton

The amino acid sequence of the N-terminal 139 residues of the L (light) chain derived from a homogeneous rabbit antibody to type III pneumococci was determined. This L chain, designated BS-5, exhibits a greater degree of homology with the basic sequence of human κ chains of subgroup I (72%) than with subgroups II and III. L-chain BS-5 differs from another L chain (BS-1), also derived from an antibody to type III pneumococci (Jaton, 1974), by eight amino acid residues, even though the chains are identical within the N-terminal 30 residues. Six of these eight substitutions are located within the three hypervariable sections of the variable half: Asn/Ser in position 31, Glu/Ala in position 55, Asx/Thr, Thr/Gly, Thr/Gly and Val/Tyr in positions 92, 94, 96 and 97 respectively. The two anti-pneumococcal L chains BS-1 and BS-5 are much more similar to each other than to an anti-azobenzoate L chain (Appella et al., 1973), from which they differ by 30 and 29 residues respectively. Of these interchanges 13–15 are confined to the three hypervariable sections, and 11 occur within the N-terminal 27 positions. The three chains have an identical sequence from residue 98 to residue 139, except for a possible inversion of two residues in positions 130–131 of the anti-azobenzoate chain.


1984 ◽  
Vol 160 (3) ◽  
pp. 893-904 ◽  
Author(s):  
B Pons-Estel ◽  
F Goñi ◽  
A Solomon ◽  
B Frangione

Light chains of the serologically and chemically defined V region sub-subgroup kappa IIIb are preferentially associated with several types of human IgM kappa (monoclonal) autoantibodies and are remarkably homologous in primary structure, as evidenced by partial amino acid sequence data. To establish the extent of homology among such proteins, we have determined the complete variable region (V) sequence of the light chains of four monoclonal IgM kappa autoantibodies, of which two (GAR and GOT) are rheumatoid factors (RFs), the third (SON) has anti-apo beta lipoprotein specificity, and the fourth (PIE) binds specifically to intermediate filaments. The region encoded by the V kappa segment gene (positions 1-95) in all four light (L) chains is virtually identical in sequence, differing by only one residue in the FR3 of protein SON and in the first CDR of protein GOT. Further, the CDR3 of kappa chain SON contains an additional residue (prolyl) located at the carboxyl-terminus of the V segment. The region encoded by the J gene (positions 96-108) is identical after position 96 for the two RFs GAR and GOT (J kappa 2), but different in proteins SON (J kappa 4) and PIE (J kappa 1). The amino acid residue at position 96, located in CDR3 at the site of combinatoriaL joining of the V kappa and J kappa gene segments and involved as a contacting residue in the hapten binding site, is different in all four light chains. These results demonstrate the extensive homology in sequence among light chains of IgM kappa autoantibodies and indicate that a particular V kappa germ line gene, kappa IIIb, is expressed as a phylogenetic response to certain self antigens or as part of a selection process by which these autoimmune responses are regulated.


2021 ◽  
Vol 22 (3) ◽  
pp. 1018
Author(s):  
Hiroaki Yokota

Helicases are nucleic acid-unwinding enzymes that are involved in the maintenance of genome integrity. Several parts of the amino acid sequences of helicases are very similar, and these quite well-conserved amino acid sequences are termed “helicase motifs”. Previous studies by X-ray crystallography and single-molecule measurements have suggested a common underlying mechanism for their function. These studies indicate the role of the helicase motifs in unwinding nucleic acids. In contrast, the sequence and length of the C-terminal amino acids of helicases are highly variable. In this paper, I review past and recent studies that proposed helicase mechanisms and studies that investigated the roles of the C-terminal amino acids on helicase and dimerization activities, primarily on the non-hexermeric Escherichia coli (E. coli) UvrD helicase. Then, I center on my recent study of single-molecule direct visualization of a UvrD mutant lacking the C-terminal 40 amino acids (UvrDΔ40C) used in studies proposing the monomer helicase model. The study demonstrated that multiple UvrDΔ40C molecules jointly participated in DNA unwinding, presumably by forming an oligomer. Thus, the single-molecule observation addressed how the C-terminal amino acids affect the number of helicases bound to DNA, oligomerization, and unwinding activity, which can be applied to other helicases.


1973 ◽  
Vol 131 (3) ◽  
pp. 485-498 ◽  
Author(s):  
R. P. Ambler ◽  
Margaret Wynn

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.


2001 ◽  
Vol 75 (17) ◽  
pp. 8127-8136 ◽  
Author(s):  
Daniel R. Perez ◽  
Ruben O. Donis

ABSTRACT Influenza A virus expresses three viral polymerase (P) subunits—PB1, PB2, and PA—all of which are essential for RNA and viral replication. The functions of P proteins in transcription and replication have been partially elucidated, yet some of these functions seem to be dependent on the formation of a heterotrimer for optimal viral RNA transcription and replication. Although it is conceivable that heterotrimer subunit interactions may allow a more efficient catalysis, direct evidence of their essentiality for viral replication is lacking. Biochemical studies addressing the molecular anatomy of the P complexes have revealed direct interactions between PB1 and PB2 as well as between PB1 and PA. Previous studies have shown that the N-terminal 48 amino acids of PB1, termed domain α, contain the residues required for binding PA. We report here the refined mapping of the amino acid sequences within this small region of PB1 that are indispensable for binding PA by deletion mutagenesis of PB1 in a two-hybrid assay. Subsequently, we used site-directed mutagenesis to identify the critical amino acid residues of PB1 for interaction with PA in vivo. The first 12 amino acids of PB1 were found to constitute the core of the interaction interface, thus narrowing the previous boundaries of domain α. The role of the minimal PB1 domain α in influenza virus gene expression and genome replication was subsequently analyzed by evaluating the activity of a set of PB1 mutants in a model reporter minigenome system. A strong correlation was observed between a functional PA binding site on PB1 and P activity. Influenza viruses bearing mutant PB1 genes were recovered using a plasmid-based influenza virus reverse genetics system. Interestingly, mutations that rendered PB1 unable to bind PA were either nonviable or severely growth impaired. These data are consistent with an essential role for the N terminus of PB1 in binding PA, P activity, and virus growth.


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