scholarly journals Sequence studies of the Fd section of the heavy chain of rabbit immunoglobulin G

1970 ◽  
Vol 116 (2) ◽  
pp. 249-259 ◽  
Author(s):  
R. G. Fruchter ◽  
S. A. Jackson ◽  
L. E. Mole ◽  
R. R. Porter
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Immunoglobulin G ◽  
Partial Amino Acid Sequence ◽  
Limited Region ◽  
Heavy Chains ◽  
Total Sequence ◽  
Continuous Sequence ◽  
Rabbit Immunoglobulin

A partial amino acid sequence was given by Cebra, Steiner & Porter (1968b) of the N-terminal half of the heavy chain of rabbit immunoglobulin G. This was extended and in part corrected to give a continuous sequence of 136 residues, which together with other work accounts for three-quarters of the total sequence. Evidence is given suggesting that there is a limited region of 10–15 residues that are exceptionally variable in the heavy chains from pooled rabbit immunoglobulin G.

scholarly journals The partial sequence of two large peptides from the N-terminal half of heavy chains from normal rabbit immunoglobulin G

1968 ◽  
Vol 107 (1) ◽  
pp. 79-88 ◽  
Author(s):  
J. J. Cebra ◽  
L. A. Steiner ◽  
R R Porter
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Immunoglobulin G ◽  
Preceding Paper ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Heavy Chains ◽  
Rabbit Immunoglobulin ◽  
Terminal Section

The partial amino acid sequence of two large peptides is described. These were prepared from the N-terminal half of the heavy chain of immunoglobulin G from pooled normal rabbit serum by tryptic digestion after the ∈-amino groups of the lysine residues had been blocked with S-ethyl trifluorothioacetate. These peptides are believed to account for about 145 residues of fragment C-1, the N-terminal section of rabbit immunoglobulin G heavy chain prepared by cyanogen bromide cleavage. The evidence from the present paper and the preceding paper (Cebra, Givol & Porter, 1968) suggests that it may be possible to deduce a predominant amino acid sequence for most, if not all, of this section of the molecule.

scholarly journals Partial amino acid sequence in the N-terminal region of an anti-pneumococcal immunoglobulin heavy chain of allotype a2

1974 ◽  
Vol 139 (1) ◽  
pp. 281-283 ◽  
Author(s):  
Jean-Claude Jaton ◽  
Joseph Haimovich
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Immunoglobulin Heavy Chain ◽  
Amino Acid Sequences ◽  
Terminal Region ◽  
Sequence Variability ◽  
Rabbit Antibody ◽  
Partial Amino Acid Sequence ◽  
Heavy Chains

The amino acid sequence of the N-terminal 48 residues of the heavy chain derived from a homogeneous rabbit antibody to type III pneumococci is described. This chain of allotype a2 is compared with other rabbit heavy chains of allotypes a1, a2 and a3. Within the N-terminal 25 positions, two chains which carry the same allotype a2 possess identical amino acid sequences, but differ markedly from heavy chains of allotypes a1 and a3. Sequence variability is observed in residues 26–27 and 30–34, but not in residues 35–48.

scholarly journals Allotype-related sequence variation of the heavy chain of rabbit immunoglobulin G

1968 ◽  
Vol 107 (6) ◽  
pp. 753-763 ◽  
Author(s):  
J. W. Prahl ◽  
R R Porter
Keyword(s):  
Amino Acid ◽  
Heavy Chain ◽  
Immunoglobulin G ◽  
Cyanogen Bromide ◽  
Amino Acid Residues ◽  
Related Sequence ◽  
Heavy Chains ◽  
Methionine Residue ◽  
Isolation And Characterization ◽  
Rabbit Immunoglobulin

The heavy chain of rabbit immunoglobulin G exists in three major allotypic patterns, Aa1–Aa3. A comparison of the amino acid compositions of the heavy chains isolated from immunoglobulin IgG homozygous for each allotypic determinant revealed the presence of an additional methionine residue per chain in the Aa3 allotype relative to the Aa1 and Aa2 allotypes. The position of the additional methionine residue was determined by cyanogen bromide cleavage and by tryptic digestion of the γ-chains; it coincided with the inter-Fd–Fc area of the chain. Isolation and characterization of the corresponding tryptic peptides of 31 amino acid residues from each of the allotypes showed the presence of a methionine-for-threonine replacement in the Aa3 allotype, but only in about 70–80% of the molecules. No other allotypic variations were seen in this tryptic peptide. Allotypically related variations in composition were also detected in the N-terminal cyanogen bromide-cleavage peptide.

Studies on the amino acid sequence of heavy chains from rabbit immunoglobulin G

1966 ◽  
Vol 166 (1003) ◽  
pp. 159-175 ◽  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Immunoglobulin G ◽  
Light Chains ◽  
Antibody Specificity ◽  
Sequence Heterogeneity ◽  
Specific Antibodies ◽  
Heavy Chains ◽  
Insight Into

It is now generally agreed that the four-chain subunit structure of Immunoglobulins which was first proposed by Porter (1962), accurately represents the gross structure of immunoglobulin G (IgG) and specific antibodies (Fleischman, Porter & Press 1963; Edelman & Gally 1964; Marler, Nelson & Tanford 1964; Nelson et al . 1965). However, an understanding of the structural basis of antibody specificity requires greater insight into the amino acid sequence of the polypeptide chain components of specific antibodies. Isolated light chains from specific antibodies and inert IgG, show a considerable degree of electrophoretic heterogeneity (Edelman & Gally 1964; Cohen & Porter 1964; Poulik 1964). Tryptic peptide maps of light chains (Nelson et al . 1965) have suggested that this heterogeneity may be accounted for by differences in amino acid sequence. This view has received considerable support from the observation that Bence-Jones proteins, which may be regarded as light chains, vary significantly in amino acid sequence (Hilschman & Craig 1965; Milstein 1966; Titani, Whitley & Putman 1966). A similar but less well-defined sequence heterogeneity has been suggested to exist in the heavy chains of specific antibodies (Feinstein 1964). However, the Fc fragment of the heavy chains has been thought to possess a regular amino acid sequence which may be similar, if not identical, among all specific antibodies (Porter 1959; Nelson et al . 1965). This paper summarizes the results of studies on the amino acid sequence of heavy chains and that portion of heavy chain, Fc fragment, which is obtained on treatment of rabbit IgG with papain (Porter 1959). These studies were designed to determine how much of the amino acid sequence of heavy chain could be accounted for by a unique, regular amino acid sequence which was common to most, if not all, IgG antibodies. In addition, attempts were made to locate regions of heavy chains which varied in amino acid sequence. Although structural variants appear to occur among the heavy chains found in non-specific IgG, it would be desirable to know what portion of the heavy chain sequence is invariant among all antibodies. If antibody specificity results from sequence heterogeneity in light and heavy chains, then knowledge of the variant and invariant portions of these chains may provide insight into the nature of specific binding sites in anti-­bodies.

scholarly journals Sequence studies on the constant region of the Fd sections of rabbit immunoglobulin G of different allotype

1975 ◽  
Vol 151 (2) ◽  
pp. 337-349 ◽  
Author(s):  
D M Pratt ◽  
L E Mole
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Immunoglobulin G ◽  
Constant Region ◽  
Related Sequence ◽  
Variable Regions ◽  
Heavy Chains ◽  
Continuous Sequence ◽  
Rabbit Igg ◽  
Constant Section

The amino acid sequence has been completed for the constant region of the Fd fragments of heavy chains from rabbit IgG (immunoglobulin G) of allotype Aa1 and Aa3. The amino acid sequence given by Fruchter et al. [(1970) Biochem. J. 116, 249-259] for the constant region of the Fd fragment from Aa1 IgG was extended and in in part corrected to give a continuous sequence of 140 residues. No allotype-related sequence variation was found in the constant section of the Fd fragment. This evidence confirms the view that the differences in sequence between the variable regions of Aa1 and Aa3 IgG [Mole et al., (1971) Biochem. J. 124, 301-318] are responsible for the allotypic specificities.

scholarly journals Differential reduction of interchain disulphide bonds of mouse immunoglobulin G

1968 ◽  
Vol 107 (6) ◽  
pp. 823-828 ◽  
Author(s):  
Alan R. Williamson ◽  
Brigitte A. Askonas
Keyword(s):  
Heavy Chain ◽  
Immunoglobulin G ◽  
Polyacrylamide Gel Electrophoresis ◽  
Partial Reduction ◽  
Free Light Chains ◽  
Myeloma Protein ◽  
Heavy Chains ◽  
Disulphide Bonds ◽  
Rabbit Immunoglobulin ◽  
Mouse Immunoglobulin

The relative lability of the interchain disulphide bonds of mouse G2a-myeloma protein 5563 was studied as a function of 2-mercaptoethanol concentration. Analysis of partial-reduction mixtures by polyacrylamide-gel electrophoresis and microdensitometry showed that the disulphide bonds between light and heavy chains are much more susceptible to reduction than the bonds between heavy chains. At a low concentration of 2-mercaptoethanol (10mm) the major dissociable products of mouse immunoglobulin G are heavy-chain dimers and free light chains. These findings contrast with the reported behaviour of rabbit immunoglobulin G, for which the lability of inter-heavy-chain bonds was found to exceed that of the bonds linking light and heavy chains (Hong & Nisonoff, 1965); the relative stability of rabbit immunoglobulin G interchain bonds was confirmed in the present study. Examination of human immunoglobulin G and an immunoglobulin G (γ2) of guinea pig showed that at least in the majority of molecules, as with mouse immunoglobulin G, the disulphide bonds between light and heavy chains are more susceptible to reduction than the inter-heavy-chain bonds.

scholarly journals Disulphide bridges of the heavy chain of human immunoglobulin G2

1971 ◽  
Vol 121 (2) ◽  
pp. 217-225 ◽  
Author(s):  
C. Milstein ◽  
B. Frangione
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Amino Acid Sequences ◽  
Cysteic Acid ◽  
Partial Reduction ◽  
Variable Part ◽  
One Dimensional ◽  
Heavy Chains ◽  
Dimensional Electrophoresis

Amino acid sequences around the disulphide bridges of the heavy chain of an immunoglobulin of the γ2 subclass have been studied. The protein was digested with pepsin and the digest fractionated by Sephadex. Screening of the eluate by one-dimensional electrophoresis of oxidized and unoxidized samples was used as an assay and pools of fractions were prepared. Identification by diagonal electrophoresis of several inter- and intra-chain disulphide bridges was done on the pooled fractions. The inter-heavy-chain bridged peptide included four cystine residues. Comparison with proteins of other human subclasses indicated that the intrachain bridges identified are the bridges of the invariable section of γ2 heavy chains. The amino acid sequence of one cysteic acid peptide that may have been derived from the variable part of the molecule was determined. Partial reduction followed by carboxymethylation with radioactive iodoacetate of two proteins of the γ2 class showed a number of labelled peptides that could be identified as being related to the inter-chain bonded cystine residues.

scholarly journals Allotypically related sequences in the Fd fragment of rabbit immunoglobulin heavy chains

1971 ◽  
Vol 124 (2) ◽  
pp. 301-318 ◽  
Author(s):  
L. E. Mole ◽  
S. A. Jackson ◽  
R. R. Porter ◽  
J. M. Wilkinson
Keyword(s):  
Heavy Chain ◽  
Immunoglobulin G ◽  
Sequence Variation ◽  
Variable Region ◽  
Related Sequence ◽  
Heavy Chains ◽  
Rabbit Immunoglobulin ◽  
Variable Section ◽  
Terminal Section ◽  
Constant Section

The sequence has been completed of the N-terminal 94 residues of the variable section of the Fd fragment of heavy chains from rabbit immunoglobulin G (IgG) of allotype As1. Most of the sequence of the same section from IgG of allotype Aa3 is also reported. These results, in conjunction with a substantial sequence of the variable region of allotype Aa2 reported elsewhere (Fleischman, 1971), show the presence of 16 positions (including six consecutive positions) in which the residue present correlates with the allotype. No allotype-related sequence variation has been found in the constant section of the Fd fragment. This evidence supports the view that two genes code for the heavy chain and it can be used as evidence in favour of somatic mutation as the origin of the variability in the sequence of the N-terminal section. The evolutionary origin of the ‘a’ locus allotypes of rabbit immunoglobulins remains obscure.

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