Chemical structure of light chains: amino acid sequence of type K Bence-Jones proteins

Bence-Jones proteins are the light chains of the autologous myeloma globulin and are analogous to the light chains of normal human immunoglobulins. Peptide mapping has demonstrated that Bence-Jones proteins share a fixed portion of their sequence (the ‘constant’ portion) and also have a mutable part (the ‘variable’ portion). Sequence analysis and ordering of the tryptic and chymotryptic peptides has provided the tentative complete amino acid sequence of one Bence-Jones protein of antigenic type K. Comparison with partial sequence data for other type K Bence-Jones proteins has revealed many structural differences in the amino terminal half of the molecules, but only one structural difference in the carboxyl terminal half. The latter is strongly correlated with the Inv genetic factor. The points of interchange in the amino terminal half occur in clusters close to the half cystine residues and the ‘switch peptide’ (positions 102 through 105), after which the sequence becomes essentially invariant. This suggests that the major areas subject to sequence variation are part of a single topographical region which may define a portion of the antigen combining site in the light chains of antibodies. Many, but not all, the amino acid interchanges are compatible with a single point mutation. As yet, no single mutational theory suffices to explain the manifold differences in structure of the light chains. Such structural variation, however, could result from the presence of many related genes.

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Amino Acid Sequence Requirements in the Hinge of Human Immunoglobulin A1 (IgA1) for Cleavage by Streptococcal IgA1 Proteases

Infection and Immunity ◽

10.1128/iai.71.3.1462-1469.2003 ◽

2003 ◽

Vol 71 (3) ◽

pp. 1462-1469 ◽

Cited By ~ 34

Author(s):

Margaret R. Batten ◽

Bernard W. Senior ◽

Mogens Kilian ◽

Jenny M. Woof

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Single Point ◽

Point Mutations ◽

Peptide Bond ◽

Human Immunoglobulin ◽

Single Point Mutation ◽

Absolute Requirement ◽

Iga1 Protease ◽

Sequence Requirements

ABSTRACT The amino acid sequence requirements in the hinge of human immunoglobulin A1 (IgA1) for cleavage by IgA1 proteases of different species of Streptococcus were investigated. Recombinant IgA1 antibodies were generated with point mutations at proline 227 and threonine 228, the residues lying on either side of the peptide bond at which all streptococcal IgA1 proteases cleave wild-type human IgA1. The amino acid substitutions produced no major effect upon the structure of the mutant IgA1 antibodies or their functional ability to bind to Fcα receptors. However, the substitutions had a substantial effect upon sensitivity to cleavage with some streptococcal IgA1 proteases, with, in some cases, a single point mutation rendering the antibody resistant to a particular IgA1 protease. This effect was least marked with the IgA1 protease from Streptococcus pneumoniae, which showed no absolute requirement for either proline or threonine at residues 227 to 228. By contrast, the IgA1 proteases of Streptococcus oralis, Streptococcus sanguis, and Streptococcus mitis had an absolute requirement for proline at 227 but not for threonine at 228, which could be replaced by valine. There was evidence in S. mitis that proteases from different strains may have different amino acid requirements for cleavage. Remarkably, some streptococcal proteases appeared able to cleave the hinge at a distant alternative site if substitution prevented efficient cleavage of the original site. Hence, this study has identified key residues required for the recognition of the IgA1 hinge as a substrate by streptococcal IgA1 proteases, and it marks a preliminary step towards development of specific enzyme inhibitors.

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A STUDY OF IMMUNOGLOBULIN STRUCTURE

Journal of Experimental Medicine ◽

10.1084/jem.124.3.307 ◽

1966 ◽

Vol 124 (3) ◽

pp. 307-330 ◽

Cited By ~ 16

Author(s):

C. Baglioni ◽

D. Cioli

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Peptide Mapping ◽

Gel Filtration ◽

Bence Jones Protein ◽

Type K ◽

The Common ◽

L Proteins ◽

Peptide Maps ◽

Bence Jones Proteins

Urinary proteins of patients with myeloma, prepared by precipitation with ammonium sulphate, have been separated by gel filtration on Sephadex G-100 after reduction and aminoethylation. Many specimens separated into a major peak of Bence Jones protein and into minor peaks of albumin, a protein tentatively identified with heavy chain and a smaller molecular weight protein corresponding to the variable portion of the corresponding Bence Jones protein. The Bence Jones protein purified by gel filtration was analyzed by electrophoresis and by peptide mapping after tryptic digestion. The peptide maps of 24 type K and 20 type L Bence Jones proteins were compared. A set of common peptides was identified in the peptide maps of the Bence Jones proteins of the same type; the common peptides of type K proteins were completely different from the common peptides of type L proteins. The patterns of distinctive peptides was compared; no similarities were found between distinctive peptides of type K and of type L proteins. Some similarities were observed in the distinctive peptides of proteins of the same type. The similarities involved in many cases peptides containing cysteine, whereas similarities in other peptides were limited. This observation suggested that the amino acid sequence around the cysteines of the variable NH2-terminal half of the Bence Jones proteins may show less variability than other sequences. A few proteins of the same type differed in all their distinctive peptides, an indication that multiple amino acid differences exist between individual Bence Jones proteins. The genetic mechanisms responsible for the variability in the amino acid sequence of the NH2-terminal half of the light chains of immunoglobulins are discussed in view of the results of the comparison by peptide mapping of the Bence Jones proteins.

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Dissociation of ϰ- and λ-chains from reduced human immunoglobulins

Biochemical Journal ◽

10.1042/bj0970460 ◽

1965 ◽

Vol 97 (2) ◽

pp. 460-465 ◽

Cited By ~ 26

Author(s):

S Cohen ◽

S Gordon

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Light Chain ◽

Human Immunoglobulin ◽

Light Chains ◽

Type K ◽

Human Immunoglobulins ◽

Starch Gels ◽

Bence Jones Proteins

1. The light chains of human immunoglobulin (Ig) exist in two forms, kappa (type K) and lambda (type L). The two types of chains can be partially separated by taking advantage of the fact that lambda-chains, for the most part, dissociate from reduced Ig at higher pH than do the kappa-chains. The same difference in dissociation of type K and L chains was observed with myeloma IgG and IgA proteins, but not with pathological IgM proteins. 2. When analysed in urea-glycine starch gels, pH7, both kappa- and lambda-chains show ten electrophoretic bands having the same mobilities as those of the whole light-chain subfractions. Normal kappa- and lambda-chains show similar differences in overall amino acid composition to those previously found with myeloma kappa- and lambda-chains and type K and L Bence-Jones proteins.

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BENCE JONES PROTEINS AND LIGHT CHAINS OF IMMUNOGLOBULINS

Journal of Experimental Medicine ◽

10.1084/jem.130.6.1295 ◽

1969 ◽

Vol 130 (6) ◽

pp. 1295-1311 ◽

Cited By ~ 29

Author(s):

Alan Solomon ◽

Carla L. McLaughlin

Keyword(s):

Light Chain ◽

Light Chains ◽

Bence Jones Protein ◽

Amino Terminal ◽

Type K ◽

Myeloma Proteins ◽

Immunoglobulin Molecule ◽

Polypeptide Chains ◽

Bence Jones Proteins

Three distinct classes of κ light polypeptide chains have been detected immunochemically by an antiserum (R185) prepared against a κ Bence Jones protein with a glutamyl amino terminal residue. This antiserum had specificity for κ light chains with glutamyl amino terminal residues and differentiated κ-chains with aspartyl amino terminal residues into two classes: the three κ-chain classes have been designated as κglu, κaspII, and κaspI. The ability of antiserum R185 to detect these antigenic differences on the intact immunoglobulin molecule, as well as on the isolated light chain or Bence Jones protein, made feasible the direct classification of type K myeloma proteins and M-macroglobulins (Waldenström). The multispecificity of the antiserum permitted the quantitation of type κglu light chains in normal, hypergammaglobulinemic, and hypogammaglobulinemic sera. Whereas the distribution of myeloma proteins and Bence Jones proteins in the κglu class correlated with the distribution of κglu chains in normal and hypergammaglobulinemic sera, the M-macroglobulins in the κglu class represented 90% of the total M-macroglobulins tested and revealed a marked divergence from the range of 24–31% of κglu immunoglobulins in normal sera. A preponderance of κglu chains was detected in the sera from patients with non-sex-linked hypogammaglobulinemia and represented 60–77% of the total type K light chain content. The controlled cleavage of a Bence Jones protein representative of each κ-chain class into its variant half and constant half made possible the localization on the light polypeptide chain, the reactive sites for which antiserum R185 had specificity. The correlations between immunochemical and structural classification of κ light chains are discussed.

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Antigenische Klassifizierung der Paraproteine und normalen Immunoglobuline vom Lambda-Typ / Paraproteins and Normal Immunoglobulins of the Lambda Type: Immunochemical Differentiation and Classification

Zeitschrift für Naturforschung B ◽

10.1515/znb-1971-1219 ◽

1971 ◽

Vol 26 (12) ◽

pp. 1292-1302 ◽

Cited By ~ 2

Author(s):

F. W. Tischendorf

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Light Chain ◽

Variable Region ◽

Basic Amino Acid ◽

Light Chains ◽

Antigenic Sites ◽

Normal Individuals ◽

Normal Light ◽

Bence Jones Proteins

The elaboration of antisera recognizing antigenic sites of the variable region of pathological immunoglobulin λ chains (Bence-Jones-proteins) is described. The antisera react with the (St+) marker carried by Bence-Jones-proteins of the basic amino-acid sequence VλI and the (111+) marker carried by L-chains of the basic sequence VλIII. With these antisera three specificityregion subtypes of human λ immunoglobulin chains could be distinguished antigenically. Twenty randomly chosen normal individuals were shown to be associated with λ chains of both basic sequences, VλI and VλIII. The results provide evidence for the non-allelic nature of the two aminoterminal light chain forms (p<0.001) and suggest that the basic sequences VλI and VλIII of Bence-Jones-proteins represent two distinct subgroups of normal light chains.

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Amino-terminal amino acid sequence and heterogeneity in glycosylation of rat renal renin.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(20)89607-0 ◽

1991 ◽

Vol 266 (11) ◽

pp. 7044-7050

Author(s):

S Kim ◽

M Hosoi ◽

N Kikuchi ◽

K Yamamoto

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Terminal Amino Acid ◽

Amino Terminal ◽

Terminal Amino ◽

Terminal Amino Acid Sequence

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A Single Point Mutation, Asn16→Lys, Dictates the Temperature-Sensitivity of the Reovirus tsG453 Mutant

Viruses ◽

10.3390/v13020289 ◽

2021 ◽

Vol 13 (2) ◽

pp. 289

Author(s):

Kathleen K. M. Glover ◽

Danica M. Sutherland ◽

Terence S. Dermody ◽

Kevin M. Coombs

Keyword(s):

Amino Acid ◽

Temperature Sensitivity ◽

Reverse Genetics ◽

Core Protein ◽

Single Point ◽

Single Amino Acid ◽

Single Point Mutation ◽

Temperature Sensitive ◽

Amino Acid Substitutions ◽

Gene Encoding

Studies of conditionally lethal mutants can help delineate the structure-function relationships of biomolecules. Temperature-sensitive (ts) mammalian reovirus (MRV) mutants were isolated and characterized many years ago. Two of the most well-defined MRV ts mutants are tsC447, which contains mutations in the S2 gene encoding viral core protein σ2, and tsG453, which contains mutations in the S4 gene encoding major outer-capsid protein σ3. Because many MRV ts mutants, including both tsC447 and tsG453, encode multiple amino acid substitutions, the specific amino acid substitutions responsible for the ts phenotype are unknown. We used reverse genetics to recover recombinant reoviruses containing the single amino acid polymorphisms present in ts mutants tsC447 and tsG453 and assessed the recombinant viruses for temperature-sensitivity by efficiency-of-plating assays. Of the three amino acid substitutions in the tsG453 S4 gene, Asn16-Lys was solely responsible for the tsG453ts phenotype. Additionally, the mutant tsC447 Ala188-Val mutation did not induce a temperature-sensitive phenotype. This study is the first to employ reverse genetics to identify the dominant amino acid substitutions responsible for the tsC447 and tsG453 mutations and relate these substitutions to respective phenotypes. Further studies of other MRV ts mutants are warranted to define the sequence polymorphisms responsible for temperature sensitivity.

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