scholarly journals Glutamine as a precursor to N-terminal pyrrolid-2-one-5-carboxylic acid in mouse immunoglobulin λ-type light chains. Amino acid-sequence variability at the N-terminal extra piece of λ-type light-chain precursors

1977 ◽  
Vol 165 (2) ◽  
pp. 347-354 ◽  
Author(s):  
Yigal Burstein ◽  
Israel Schechter

The mRNA molecules coding for three mouse immunoglobulin λ-type light (L) chains (MOPC-104E λ1, RPC-20 λ1, MOPC-315 λ2) programme the cell-free synthesis of precursors larger than the mature proteins. Radioactive amino acid-sequence analyses of each of the three precursors labelled with [3H]alanine, [3H]serine, [3H]glutamine, [3H]glutamic acid and [3H]threonine showed that an extra piece, at least 18 residues long, is linked to the N-terminus of the mature L-chains. The N-terminal extra-peptide segment may be 19 residues long, since analyses of precursors labelled with [35S]methionine indicated an additional N-terminal methionine residue which was recovered in low yields. Presumably this is the initiator methionine, which is known to be short lived in eukaryotes. The mature forms of MOPC-104E, RPC-20 and MOPC-315 λ L-chains are blocked at the N-termini by pyrrolid-2-one-5-carboxylic acid (pyroglutamic acid). Sequence analyses of precursors labelled with [3H]glutamine and [3H]glutamic acid showed incorporation only of glutamine in a position that matches with the position of pyrrolid-2-one-5-carboxylic acid in the mature forms of all three precursors, and incorporation of glutamic acid in other positions. The data showed the absence of glutamine–glutamic acid interconversion, since the radioactive peaks obtained from either3H-labelled amino acid were discrete, and free from cross-contamination. These results prove that glutamine is the precursor amino acid of pyrrolid-2-one-5-carboxylic acid at the N-termini of the mature MOPC-104E λ1, RPC-20 λ1 and MOPC-315 λ2 L-chains. Thus the formation of pyrrolid-2-one-5-carboxylic acid by cyclization of glutamine is a post-translational event which occurs after, or concomitant with, cleavage of the extra piece from the precursor to yield the mature L-chain. The variable (V) regions (110 amino acid residues) of mouse λ L-chains are quite similar: when compared with that of MOPC-104E λ1 chain, the V-region of RPC-20 λ1 chain differs in one residue, and the V-region of MOPC-315 λ2 chain differs in 11 residues. The partial sequence data show that the N-terminal extra pieces of the two λ1 L-chain precursors have, so far, identical partial sequences; the extra piece of the λ2 L-chain precursor differs from these in at least three out of 19 positions.

1989 ◽  
Vol 54 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Ivan Kluh ◽  
Ladislav Morávek ◽  
Manfred Pavlík

Cyanogen bromide fragment CB5 represents the region of the polypeptide chain of hemopexin between the fourth and fifth methionine residue (residues 232-352). It contains 120 amino acid residues in the following sequence: Arg-Cys-Ser-Pro-His-Leu-Val-Leu-Ser-Ala-Leu-Thr-Ser-Asp-Asn-His-Gly-Ala-Thr-Tyr-Ala-Phe-Ser-Gly-Thr-His-Tyr-Trp-Arg-Leu-Asp-Thr-Ser-Arg-Asp-Gly-Trp-His-Ser-Trp-Pro-Ile-Ala-His-Gln-Trp-Pro-Gln-Gly-Pro-Ser-Ala-Val-Asp-Ala-Ala-Phe-Ser-Trp-Glu-Glu-Lys-Leu-Tyr-Leu-Val-Gln-Gly-Thr-Gln-Val-Tyr-Val-Phe-Leu-Thr-Lys-Gly-Gly-Tyr-Thr-Leu-Val-Ser-Gly-Tyr-Pro-Lys-Arg-Leu-Glu-Lys-Glu-Val-Gly-Thr-Pro-His-Gly-Ile-Ile-Leu-Asp-Ser-Val-Asp-Ala-Ala-Phe-Ile-Cys-Pro-Gly-Ser-Ser-Arg-Leu-His-Ile-Met. The sequence was derived from the data on peptides prepared by cleavage of fragment CB5 by mild acid hydrolysis, by trypsin and chymotrypsin.


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.


1981 ◽  
Vol 193 (3) ◽  
pp. 899-906 ◽  
Author(s):  
H S Kim ◽  
N Tamiya

The venom of an Australian elapid snake, the common death adder (Acanthophis antarcticus), was chromatographed on a CM-cellulose CM52 column. One of the neurotoxic components, Acanthophis antarcticus b (toxin Aa b) was isolated in about 9.4% (A280) yield. The complete amino acid sequence of toxin Aa b was elucidated. Toxin Aa b is composed of 73 amino acid residues, with ten half-cystine residues, and has a formula weight of 8135. Toxin Aa b has no histidine or methionine residue in its sequence. The amino acid sequence of toxin Aa b is homologous with those of other neurotoxins with known sequences, although it is novel in having a valine residue at its N-terminus and an arginine residue at position-23, where a lysine residue is found in almost all the so-far-known neurotoxins. Irrespective of the latter replacement, the toxin Aa b is fully active, with an LD50 value (in mice) of 0.13 microgram/g body weight on intramuscular injection.


1978 ◽  
Vol 173 (3) ◽  
pp. 863-868 ◽  
Author(s):  
K B Reid ◽  
E O Thompson

The amino acid sequence of the N-terminal 108 residues of the B chain of subcomponent C1q of the first component of human complement was determined. The B chain has a blocked N-terminal amino acid, which was judged to be 5-oxopyrrolidine-2-carboxylic acid. A collagen-like region of 84 residues was found, which started at position B-6, and all of the six hydroxylysine residues and 12 hydroxyproline residues present in the chain were found in this region. Four of the six hydroxylysine residues may be glycosylated. The repeating nature of the collagen-like region is broken at position B-9, where alanine is found in a position where glycine would be expected. The exact position of the interchain disulphide bond joining the A and B chains of human subcomponent C1q was shown to be between residues A4 and B4.


1976 ◽  
Vol 54 (10) ◽  
pp. 902-914 ◽  
Author(s):  
Anne Cunningham ◽  
Hsin-Min Wang ◽  
Stephen R. Jones ◽  
Alexander Kurosky ◽  
Leticia Rao ◽  
...  

The digest of penicillopepsin (EC 3.4.23.7) with protease II from Myxobacter AL-1 gave five fragments which were separated on a Biogel P-100 column in 70% formic acid. The fragments were from 16 to 125 amino acids long. Two fragments were also isolated from a digest with a protease from Staphylococcus aureus. The analysis of these fragments by automatic sequencer gave a number of overlaps of the chymotryptic and thermolytic peptides. The available amino acid sequence data for penicillopepsin described in this paper and the accompanying papers (Kurosky, A. &Hofmann, T.: Can. J. Biochem. 54, 872 (1976); Rao, L. &Hofmann, T.: Can. J. Biochem. 54, 885 (1976); Harris, C. I., Rao, L., Shutsa, P., Kurosky, A. &Hofmann, T.: Can. J. Biochem. 54, 895 (1976)) have been combined and yield 15 fragments which range in lengths from 3 to 112 amino acid residues. These unique fragments account for virtually all the amino acids of the fungal protease. Four of the fragments with a total of 194 residues (about 60% of the molecule) have been aligned with corresponding sections of pig pepsin (EC 3.4.23.1) and with part of the N-terminal sequence available for calf chymosin (EC 3.4.23.4). In the alignments about 37% of the residues in the fungal enzyme are identical with at least one of the mammalian enzymes. An additional 20% are chemically similar. These results, together with previously reported active-site directed modifications, show conclusively that penicillopepsin is an evolutionary homologue of the mammalian acid proteases.


1985 ◽  
Vol 50 (4) ◽  
pp. 885-896 ◽  
Author(s):  
Bedřich Meloun ◽  
Miroslav Baudyš ◽  
Manfred Pavlík ◽  
Vladimír Kostka ◽  
Gert Hausdorf ◽  
...  

The large cyanogen bromide fragment (CB1) represents the N-terminal part of the molecule of thermitase and contains 226 amino acid residues. Its molecular weight calculated from sequential data is 22 932 (the C-terminal residue is regarded as a methionine residue in the calculations). The amino acid sequence of fragment CB1 was determined by analysis of peptides obtained by tryptic hydrolysis of the fragment; these data were complemented by sequence analysis of the chymotryptic digest of fragment Mf (residues 75 through 226) and of chymotryptic fragment ET3 (residues 103 through 226) isolated from the limited tryptic digest of fragment CB1. The peptides were purified by high performance liquid chromatography and by thin layer techniques. The sequence analysis of the large peptides was effected in the sequenator, small peptides were sequenced manually by the DABITC/PITC double coupling technique. The results obtained in this study together with those of previous work5 permitted the complete amino acid sequence of fragment CB1 to be determined.


1979 ◽  
Vol 179 (2) ◽  
pp. 367-371 ◽  
Author(s):  
K B M Reid

The sequences of amino acid residues 38–51 of the A-chain, and residues 42–90 of the C-chain, of human subcomponent C1q are given. These results, along with previously published sequence data [Reid (1974) Biochem.J. 141, 189–203; Reid (1977) Biochem.J. 161, 247–251; Reid & Thompson (1978) Biochem.J. 173, 863–868] allow the presentation, and comparison with each other, of the complete amino acid sequences of the collagen-like regions found in the A-, B- and C-chains of human subcomponent C1q. Each chain has the continuity of its collagen-like Gly-X-Y repeating triplet amino acid sequence broken. The B- and C-chains have alanine residues at positions B-9 and C-36 where glycine might be expected. The A-chain has a threonine residue at position A-39, which is located between two Gly-X-Y triplets.


1982 ◽  
Vol 207 (1) ◽  
pp. 91-95 ◽  
Author(s):  
C W Ward ◽  
T C Elleman ◽  
A A Azad

The amino acid sequence of the Pronase-released heads of neuraminidase subtype N2 from the A/Tokyo/3/67 strain of influenza virus was determined by a combination of peptide and nucleic acid sequence analysis. The results show that the Pronase-released heads contain 396 amino acid residues and extend from residue 74 in the original protein to the C-terminus at residue 469. The heads contain five potential glycosylation sites at asparagine residues 86, 146, 200, 234 and 402, but only the first four are glycosylated. The sequence homology with the corresponding region of the previously published sequence of the neuraminidase subtype N1 [Fields, Winter & Brownlee (1981) Nature (London) 290, 213-217] is 45%. Detailed evidence for the sequence data has been deposited as Supplementary Publication SUP 50116 (14 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1981) 193, 5.


1979 ◽  
Vol 44 (9) ◽  
pp. 2710-2721 ◽  
Author(s):  
Bedřich Meloun ◽  
Dana Čechová

The molecule of the inhibitor contains 57 amino acid residues whose sequence is the following: Pyr-Gly-Ala-Gln-Val-Asp-Cys-Ala-Glu-Phe-Lys-Asp-Pro-Lys-Val-Tyr-Cys-Thr-Arg-His-Ser-Asp-Pro-Gln-Cys-Gly-Ser-Asn-Gly-Glu-Thr-Tyr-Gly-Asn-Lys-Cys-Ala-Phe-Cys-Lys-Ala-Val-Met-Lys-Ser-Gly-Gly-Lys-Ile-Asn-Leu-Lys-His-Arg-Gly-Cys-Lys. The N-terminal group of the inhibitor is pyrrolidone carboxylic acid. The sequential data were obtained by analyses of peptides isolated from tryptic and chymotryptic digests of the oxidized or carboxymethylated inhibitor. The molecular weight of the inhibitor is 6 200.


1997 ◽  
Vol 75 (6) ◽  
pp. 687-696 ◽  
Author(s):  
Tamo Fukamizo ◽  
Ryszard Brzezinski

Novel information on the structure and function of chitosanase, which hydrolyzes the beta -1,4-glycosidic linkage of chitosan, has accumulated in recent years. The cloning of the chitosanase gene from Streptomyces sp. strain N174 and the establishment of an efficient expression system using Streptomyces lividans TK24 have contributed to these advances. Amino acid sequence comparisons of the chitosanases that have been sequenced to date revealed a significant homology in the N-terminal module. From energy minimization based on the X-ray crystal structure of Streptomyces sp. strain N174 chitosanase, the substrate binding cleft of this enzyme was estimated to be composed of six monosaccharide binding subsites. The hydrolytic reaction takes place at the center of the binding cleft with an inverting mechanism. Site-directed mutagenesis of the carboxylic amino acid residues that are conserved revealed that Glu-22 and Asp-40 are the catalytic residues. The tryptophan residues in the chitosanase do not participate directly in the substrate binding but stabilize the protein structure by interacting with hydrophobic and carboxylic side chains of the other amino acid residues. Structural and functional similarities were found between chitosanase, barley chitinase, bacteriophage T4 lysozyme, and goose egg white lysozyme, even though these proteins share no sequence similarities. This information can be helpful for the design of new chitinolytic enzymes that can be applied to carbohydrate engineering, biological control of phytopathogens, and other fields including chitinous polysaccharide degradation. Key words: chitosanase, amino acid sequence, overexpression system, reaction mechanism, site-directed mutagenesis.


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