scholarly journals Complete amino acid sequences of the three collagen-like regions present in subcomponent C1q of the first component of human complement

1979 ◽  
Vol 179 (2) ◽  
pp. 367-371 ◽  
Author(s):  
K B M Reid
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Data ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Human Complement ◽  
Threonine Residue ◽  
A Chain

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.

scholarly journals Completion of the amino acid sequences of the A and B chains of subcomponent C1q of the first component of human complement

1982 ◽  
Vol 203 (3) ◽  
pp. 559-569 ◽  
Author(s):  
K B M Reid ◽  
J Gagnon ◽  
J Frampton
Keyword(s):  
Amino Acid ◽  
Structure Prediction ◽  
Sequence Data ◽  
Helical Structure ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Human Complement ◽  
Major Site ◽  
A Chain ◽  
Asparagine Residue

The sequences of amino acid residues 109-224 of the A chain, and residues 109-22 of the B chain, of human subcomponent C1q are given. These results, along with previously published sequence data on the N-terminal, collagen-like, regions of the A and B chains [Reid (1979) Biochem. J. 179, 367-371] yield the complete amino acid sequences of the A and B chains of subcomponent C1q. The asparagine residue at position A-124 has been identified as the major site of asparagine-linked carbohydrate in subcomponent C1q. When the sequences of the C-terminal, 135-residue-long, ‘globular’ regions of A and B chains are compared they show 40% homology. The degree of homology over certain stretches of 15-20 residues, within the C-terminal regions, rises up to values of 73%, indicating the presence of strongly conserved structures. Structure prediction studies indicate that both the A and B chain C-terminal regions may adopt a predominantly beta-type structure with apparently little alpha-helical structure.

scholarly journals Amino acid sequence of the N-terminal forty-two amino acid residues of the C chain of subcomponent C1q of the first component of human complement

1977 ◽  
Vol 161 (2) ◽  
pp. 247-251 ◽  
Author(s):  
K B M Reid
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Triple Helix ◽  
Amino Acid Sequences ◽  
Sequence Information ◽  
Amino Acid Residues ◽  
Human Complement ◽  
Helix Formation ◽  
Triple Helix Formation ◽  
Protein Sequencer

1. The sequence of the N-terminal 42 amino acid residues and the identity of residue 45 of the C chain of subcomponent C1q were established by the use of the automatic protein sequencer. 2. A comparison of the amino acid sequences of the A and C chains of subcomponent C1q shows that they are identical at 18 positions out of the first 45. However, 12 of the amino acid residues in the positions of identity are glycine residues occurring in the repeating triplet sequence Gly-X-Y. 3. Position 36 in the C chain was found to be alanine, which was unexpected since the residue in this position would have to be glycine if the repeating triplet sequence Gly-X-Y were to extend, uniformly, throughout the entire length of the C-chain collagen-like region. This break in the repeating triplet sequence would prevent residue 36 in the C chain from taking part in collagen-like triple-helix formation. 4. The sequence information presented here therefore indicates that there should be a break, or distortion, located approximately half-way along each of the six collagen-like triple-helical regions proposed to be present in subcomponent C1q [Reid & Porter (1976) Biochem. J. 155, 19-23] and this is consistent with what is seen in electron micrographs of intact and pepsin-digested subcomponent C1q.

scholarly journals Diarrhea-Inducing Activity of Avian Rotavirus NSP4 Glycoproteins, Which Differ Greatly from Mammalian Rotavirus NSP4 Glycoproteins in Deduced Amino Acid Sequence, in Suckling Mice

2002 ◽  
Vol 76 (11) ◽  
pp. 5829-5834 ◽  
Author(s):  
Yoshio Mori ◽  
Mohammed Ali Borgan ◽  
Naoto Ito ◽  
Makoto Sugiyama ◽  
Nobuyuki Minamoto
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Suckling Mice

ABSTRACT Avian rotavirus NSP4 glycoproteins expressed in Escherichia coli acted as enterotoxins in suckling mice, as did mammalian rotavirus NSP4 glycoproteins, despite great differences in the amino acid sequences. The enterotoxin domain of PO-13 NSP4 exists in amino acid residues 109 to 135, a region similar to that reported in SA11 NSP4.

scholarly journals The principal site of glycation of human complement factor B

1991 ◽  
Vol 274 (2) ◽  
pp. 473-480 ◽  
Author(s):  
M A Niemann ◽  
A S Bhown ◽  
E J Miller
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Data ◽  
Complement Factor ◽  
Human Complement ◽  
Factor B ◽  
Complement Factor B ◽  
Functional Regions ◽  
High Concentrations

Accumulating amino acid sequence data have made it increasingly evident that many essential complement proteins have potentially modifiable lysine residues in putative critical functional regions. Evidence is now presented that glucose is covalently attached to lysine-266 of purified human complement Factor B as a result of glycation. Purified B was treated with NaB3H4, which reduces such bound glucose to a mixture of radiolabelled hexitols. Amino acid analysis revealed the expected radiolabelled hexitol-lysine epimers. In addition, fluorography of dried gels resolving the major high-molecular-mass h.p.l.c.-fractionated CNBr-cleavage peptides of NaB3H4-reduced B indicated that this radioactivity was specifically associated with the 15 kDa fragment derived from the N-terminal region of fragment Bb. Amino acid sequence analysis suggested that the C-terminal lysine (residue 266 of B) of the N-terminal Lys-Lys doublet of this peptide is preferentially modified. If such glycation can subsequently be shown to occur in vivo, then perhaps this modification might also be found to affect the functional activity of B and offer a potential explanation for some of the immunopathological complications of diseases exposing key plasma proteins, such as this active-site-containing proteinase of the multimeric alternative-complement-pathway C3/C5 convertases, to long-term high concentrations of glucose, such as the decreased resistance to infection and impaired chemotaxis and phagocytosis characteristic of diabetes.

scholarly journals Molecular cloning of a cDNA encoding the glycoprotein of hen oviduct microsomal signal peptidase

1992 ◽  
Vol 282 (2) ◽  
pp. 447-452 ◽  
Author(s):  
A L Newsome ◽  
J W McLean ◽  
M O Lively
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Immunoblot Analysis ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Signal Peptidase ◽  
Amino Acid Residues ◽  
Protein Subunit ◽  
Chicken Oviduct ◽  
Dog Pancreas

Detergent-solubilized hen oviduct signal peptidase has been characterized previously as an apparent complex of a 19 kDa protein and a 23 kDa glycoprotein (GP23) [Baker & Lively (1987) Biochemistry 26, 8561-8567]. A cDNA clone encoding GP23 from a chicken oviduct lambda gt11 cDNA library has now been characterized. The cDNA encodes a protein of 180 amino acid residues with a single site for asparagine-linked glycosylation that has been directly identified by amino acid sequence analysis of a tryptic-digest peptide containing the glycosylated site. Immunoblot analysis reveals cross-reactivity with a dog pancreas protein. Comparison of the deduced amino acid sequence of GP23 with the 22/23 kDa glycoprotein of dog microsomal signal peptidase [Shelness, Kanwar & Blobel (1988) J. Biol. Chem. 263, 17063-17070], one of five proteins associated with this enzyme, reveals that the amino acid sequences are 90% identical. Thus the signal peptidase glycoprotein is as highly conserved as the sequences of cytochromes c and b from these same species and is likely to be found in a similar form in many, if not all, vertebrate species. The data also show conclusively that the dog and avian signal peptidases have at least one protein subunit in common.

scholarly journals Studies on Monotreme Proteins. V. Amino Acid Sequence of the a-Chain of Haemoglobin From the Platypus, Ornithorhynchus anatinus

1974 ◽  
Vol 27 (6) ◽  
pp. 591 ◽  
Author(s):  
RG Whittaker ◽  
EOP Thompson
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Tryptic Digestion ◽  
Complete Amino Acid Sequence ◽  
Ornithorhynchus Anatinus ◽  
A Chain

Blood from the platypus contained three haemoglobins which were separated by chromatography on DEAE-Sephadex. The major component, Hb-I, was converted to globin and fractionated into the oc-and p-chains by chromatography on eM-cellulose in 8M urea-thiol buffers, and the complete amino acid sequence of the 141 residues of the oc-chain were determined. Peptides derived from the oc-chain by tryptic digestion were isolated by paper ionophoresis and chromatography. The amino acid sequences were determined by the dansyl-Edman procedure or by further digestion with other enzymes.

scholarly journals Haemoglobins of the Shark, Heterodontus Portusjacksoni II. Amino Acid Sequence of the a-Chain

1976 ◽  
Vol 29 (2) ◽  
pp. 73 ◽  
Author(s):  
AR Nash ◽  
WK Fisher ◽  
EOP Thompson
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Paper Chromatography ◽  
Cyanogen Bromide ◽  
Gel Filtration ◽  
Amino Acid Sequences ◽  
Tryptic Digestion ◽  
Amino Terminal ◽  
Core Peptide ◽  
A Chain

The amino acid sequence of the a-chain of the principal haemoglobin from the shark, H. portusjacksoni has been determined. The chain has 148 residues and is acetylated at the amino terminal. The soluble peptides obtained by tryptic and chymotryptic digestion of the protein or its cyanogen bromide fragments were isolated by gel filtration, paper ionophoresis and paper chromatography. The amino acid sequences were determined by the dansyl-Edman procedure. The insoluble 'core' peptide from the tryptic digestion contained 34 residues and required cleavage by several proteases before the sequence was established. Compared with human a-chain there are 88 amino acid differences including the additional seven residues which appear on the amino terminal of the shark chain. There is also one deletion and one insertion. The chain contains no tryptophan but has four cysteinyl residues which is the highest number of such residues recorded for a vertebrate globin.

scholarly journals Isolation, characterization and sequence analysis of a full-length cDNA clone encoding acetohydroxy acid reductoisomerase from spinach chloroplasts

1991 ◽  
Vol 277 (2) ◽  
pp. 469-475 ◽  
Author(s):  
R Dumas ◽  
M Lebrun ◽  
R Douce
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Single Gene ◽  
Amino Acid Sequences ◽  
Full Length ◽  
Open Reading Frame ◽  
Amino Acid Residues ◽  
Protein Precursor ◽  
Reading Frame ◽  
Full Length Cdna

Acetohydroxy acid reductoisomerase (AHRI), the second enzyme in the parallel isoleucine/valine-biosynthetic pathway, catalyses an unusual two-step reaction in which the substrate, either 2-acetolactate or 2-aceto-2-hydroxybutyrate, is converted via an alkyl migration and an NADPH-dependent reduction to give 2,3-dihydroxy-3-methylbutyrate or 2,3-dihydroxy-3-methylvalerate respectively. We have isolated and characterized a full-length cDNA from a lambda gt11 spinach library encoding the complete acetohydroxy acid reductoisomerase protein precursor. The 2050-nucleotide sequence contains a 1785-nucleotide open reading frame. The derived amino acid sequence indicates that the protein precursor consists of 595 amino acid residues including a presequence peptide of 72 amino acid residues. The N-terminal sequence of the first 16 amino acid residues of the purified AHRI confirms the identity of the cDNA. The derived amino acid sequence from this open reading frame shows 23% identity with the deduced amino acid sequences of the Escherichia coli and Saccharomyces cerevisiae AHRI proteins. There are two blocks of conserved amino acid residues in these three proteins. One of these is a sequence similar to the ‘fingerprint’ region of the NAD(P)H-binding site found in a large number of NAD(P)H-dependent oxidoreductases. The other, a short sequence (Lys-Xaa-Xaa-Xaa-Xaa-Xaa-Xaa-Xaa-Ser-His-Gly-Phe) containing the amino acids lysine and histidine, could well be the catalytic site of the first step of the AHRI reaction. Southern-blot analysis indicated that AHRI is encoded by a single gene per haploid genome of about 7.5 kbp containing at least four introns.

scholarly journals Isolation, by partial pepsin digestion, of the three collagen-like regions present in subcomponent Clq of the first component of human complement

1976 ◽  
Vol 155 (1) ◽  
pp. 5-17 ◽  
Author(s):  
K B M Reid
Keyword(s):  
Amino Acid ◽  
Sodium Dodecyl Sulphate ◽  
Sequence Data ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Amino Acid Sequences ◽  
Disulphide Bond ◽  
Small Peptides ◽  
Molecular Weights ◽  
A Chain

1. Digestion of human subcomponent C1q with pepsin at pH4.45 for 20h at 37 degrees C fragmented most of the non-collagen-like amino acid sequences in the molecule to small peptides, whereas the entire regions of collagen-like sequence that comprised 38% by weight of the subcomponent C1q were left intact. 2. The collagen-like fraction of the digest was eluted in the void volume of a Sephadex G-200 column, was was showm to be composed of two major fragments when examined by electrophoresis on polyacrylamide gels run in buffers containing sodium dodecyl sulphate. These fragments were separated on CM-cellulose at pH4.9 in buffers containing 7.5M-urea. 3. Human subcomponent C1q on reduction and alkylation yields equimolar amounnts of three chains, which have been designated A, B and C [Reid et al. (1972) Biochem. J. 130, 749-763]. One of the pepsin fragments was shown to be composed of the N-terminal 95 residues of the A chain linked, via residue A4, by a single disulphide bond to a residue in the sequence B2-B6 in the N-terminal 91 residues of the B chain. The second pepsin fragment was shown to be composed of a disulphide-linked dimer of the N-terminal 94 residues of the C chain, the only disulphide bond being located at residue C4.4. The mol. wts. of the unoxidized and oxidized pepsin fragments were estimated from their amino acid compositions to be 20 000 and 18 200 for the A-B and C-C dimers and 11 400, 8800 and 9600 for the collagen-like fragments of the A, B and C chains respectively. Estimation of the molecular weights of the peptic fragments by polyacrylamide-gel electrophoresis run in the presence of sodium dodecyl sulphate gave values that were approx. 50% higher than expected from the amino acid sequence data. This is probably due to the high collagen-like sequence content of these fragments.

scholarly journals Amino acid sequence of the N-terminal 108 amino acid residues of the B chain of subcomponent C1q of the first component of human complement

1978 ◽  
Vol 173 (3) ◽  
pp. 863-868 ◽  
Author(s):  
K B Reid ◽  
E O Thompson
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Amino Acid Sequence ◽  
Disulphide Bond ◽  
Amino Acid Residues ◽  
Human Complement ◽  
Terminal Amino Acid ◽  
Exact Position ◽  
Terminal Amino

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.

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