scholarly journals The complete amino acid sequence of a prototype immunoglobulin-λ light-chain-type amyloid-fibril protein AR

1981 ◽  
Vol 195 (3) ◽  
pp. 561-572 ◽  
Author(s):  
K Sletten ◽  
J B Natvig ◽  
G Husby ◽  
J Juul

The amino acid sequence of an amyloid-fibril protein of immunoglobulin light-chain type (AL) was elucidated. The sequence determination involved digesting the protein with trypsin, thermolysin and pepsin. The protein was found to consist of 154 amino acid residues and is thus missing about half of the constant region of a light chain. A certain heterogeneity in the length of the polypeptide was observed in the C-terminal region. The amino acid sequence from CDR (complementary-determining region) 1 and FR (framework region) 3 indicated an oligoclonal origin of the protein. By comparing the primary structure of protein AR with other lambda- and even kappa-chains, it was revealed that protein AR had an insertion of two residues of aspartic acid, namely residues 68 and 69, which has not been reported previously in light chains. The overall sequence homology in the variable region showed that protein AR is more similar to V lambda V than to the other subgroups [Kabat, Wu & Bilofsky (1979) Variable regions of Immunoglobulin Chains, Medical Computer Systems, Bolt, Beranek and Newman, Cambridge, MA].

1985 ◽  
Vol 232 (1) ◽  
pp. 183-190 ◽  
Author(s):  
T Tveteraas ◽  
K Sletten ◽  
P Westermark

The amino acid sequence of an amyloid-fibril protein Es492 of immunoglobulin-lambda-light-chain origin (AL) was elucidated. The amyloid fibrils were obtained from the spleen of a patient who died from systemic amyloidosis. The amino acid sequence was elucidated from structural studies of peptides derived from digestion of the protein with trypsin, thermolysin, chymotrypsin and Staphylococcus aureus V8 proteinase and from cleavage of the protein with CNBr and BNPS-skatole. A heterogeneity in the length of the polypeptide was seen in the C-terminal region. The protein was by sequence homology to other lambda-chains shown to be of the V lambda II subgroup. Although an extensive homology was seen, some amino acid residues in positions 26, 31, 32, 40, 44, 93, 97, 98 and 99 have not previously been reported in these positions of V lambda II proteins. The significance of these residues in the fibril formation is unclear. The protein was found to contain carbohydrate, with glycosylation sites in two of the hypervariable regions.


1986 ◽  
Vol 239 (3) ◽  
pp. 545-551 ◽  
Author(s):  
E Holm ◽  
K Sletten ◽  
G Husby

The amino acid sequence of the variable region of a carbohydrate-containing amyloid-fibril protein MOL of immunoglobulin-light-chain type (AL) was elucidated. The sequence determination involved cleaving the protein with CNBr, BNPS-skatole, thermolysin and trypsin. The sequenced protein consisted of about 130 amino acid residues; however, gel-filtration and N-terminal analysis studies revealed AL proteins ranging in Mr from about 10,000 to 25,000. The oligosaccharide chain was found to be bound in the hypervariable region. By sequence homology to other lambda chains the AL protein MOL was shown to be of the V lambda III subgroup.


1988 ◽  
Vol 256 (3) ◽  
pp. 973-980 ◽  
Author(s):  
E M Fykse ◽  
K Sletten ◽  
G Husby ◽  
G G Cornwell

The primary structure of the variable region of an amyloid-fibril protein GIL of immunoglobulin lambda-light-chain origin (AL) was determined. The AL protein obtained from the fibrils in the spleen of a 54-year-old man with primary systemic amyloidosis could be assigned to subgroup IV of the lambda variable-region sequence. About 50% of the protein was found to be truncated in the N-terminus and lacked the first six amino acid residues. The polypeptides consisted of about 146 amino acid residues and contained traces of carbohydrate. An acceptor site for N-glycosylation was found in positions 90-93, but no glycopeptide could be isolated. Comparison of the amino acid sequence of AL protein GIL with that of the only Bence-Jones protein of subgroup IV previously studied revealed a sequence homology of 89%. A similar comparison made with other AL proteins gave sequence homologies below 66%.


1976 ◽  
Vol 157 (1) ◽  
pp. 145-151 ◽  
Author(s):  
Y Burstein ◽  
I Schechter

The proteins programmed in the wheat-germ cell-free system by the mRNA coding for the MOPC-63 mouse myeloma L (light) chain were labelled with six radioactive amino acids: [35S]methionine, [4,5-3H]leucine, [3,4-3H]proline, [3-3H]serine, [4,5-3H]isoleucine or [2,3-3H]alanine. Amino acid-sequence analyses showed that over 90% of the total cell-free product was one homogeneous protein, which corresponds to the MOPC-63 L-chain precursor. In this precursor an extra piece, 20 amino acid residues in length, precedes the N-terminus of the mature L chain. The extra piece contains one methionine residue at the N-terminus, six leucine residues, which are clustered in two triplets at positions 6, 7, 8 and 11, 12, 13, one proline residue at position 16, and one serine residue at position 18. The closely gathered leucine residues, as well as their abundance (30%), suggest that the extra-piece moiety is hydrophobic. In the precursors, the extra piece is coupled to the variable region of the L chain. Partial sequences of precursors of L chains of the same and different subgroups that were labelled with the above six radioactive amino acids indicate that the extra piece is part of the variable region. Thus the precursors of MOPC-63 and MOPC-321 L chains, which are of the same subgroup, have extra pieces of identical size (20 residues), and so far their partial sequences are also identical (see above). On the other hand, in the precursor of MOPC-41 L chain, which is of a different subgroup, the extra piece is 22 residues in length. Further, the sequence of the MOPC-41 extra piece differs in at least ten positions from sequences of the extra pieces of the precursors of MOPC-63 and MOPC-321 L chains.


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.


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