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.

Cl̄r and Cl̄s subcomponents of human complement: Two serine proteinases lacking the ‘histidine-loop’ disulphide bridge

1981 ◽  
Vol 1 (10) ◽  
pp. 779-784 ◽  
Author(s):  
Gerard J. Arlaud ◽  
Jean Gagnon
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Histidine Residue ◽  
Serine Proteinases ◽  
Human Complement ◽  
Disulphide Bridge ◽  
Terminal Amino Acid ◽  
Relay System ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

The N-terminal amino acid sequence of human Cl̄s b chain has been extended to 52 residues. The histidine residue involved in the charge-relay system is located at position 38, whereas the ‘histidine-loop’ disulphide bridge is missing. So far, human complement subcomponents Cl̄s are the only known mammalian serine proteinases lacking this disulphide bridge.

scholarly journals The overexpression and complete amino acid sequence of Escherichia coli 3-dehydroquinase

1986 ◽  
Vol 238 (2) ◽  
pp. 475-483 ◽  
Author(s):  
K Duncan ◽  
S Chaudhuri ◽  
M S Campbell ◽  
J R Coggins
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Nucleotide Sequence ◽  
Amino Acid Sequence ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Transcript Mapping ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

The enzyme 3-dehydroquinase was purified in milligram quantities from an overproducing strain of Escherichia coli. The amino acid sequence was deduced from the nucleotide sequence of the aroD gene and confirmed by determining the amino acid composition of the overproduced enzyme and its N-terminal amino acid sequence. The complete polypeptide chain consists of 240 amino acid residues and has a calculated subunit Mr of 26,377. Transcript mapping revealed that aroD is a typical monocistronic gene.

scholarly journals Isolation and properties of lysophospholipases from the venom of an Australian elapid snake, Pseudechis australis

1982 ◽  
Vol 203 (1) ◽  
pp. 269-276 ◽  
Author(s):  
C Takasaki ◽  
N Tamiya
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Phospholipase A2 ◽  
Maximum Activity ◽  
Haemolytic Activity ◽  
Amino Acid Residues ◽  
Terminal Amino Acid ◽  
Optimum Ph ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

Two lysophospholipases were isolated from the venom of an Australian elapid snake (subfamily Acanthophiinae), Pseudechis australis, by sequential chromatography on CM-52 cellulose, Sephadex G-75 and DE-52 cellulose columns. They were very similar to each other. One of them, lysophospholipase I, was obtained as a homodimer, the monomer of which consisted of 123 amino acid residues with seven disulphide bridges. The amino acid composition and the N-terminal amino acid sequence of the enzyme were similar to those of phospholipase A2, Ca2+ was required for its activity and the maximum activity was attained at 2 mM-CaCl2 in the presence of 1 mM-EDTA. The optimum pH was 7.5. Lysophospholipase I hydrolysed lysophosphatidylcholine more rapidly than lysophosphatidylethanolamine. It did not hydrolyse, however, phosphatidylcholine, 1-palmitoylglycerol, tripalmitoylglycerol or p-nitrophenyl acetate. Modification of the enzyme with p-bromophenacyl bromide or 2-nitrophenylsulphenyl chloride suppressed the activity. A strong direct haemolytic activity was exhibited when the lysophospholipase was present together with phospholipase A2.

C-Terminal amino acid sequence of chicken pepsinogen and its homology with sequences of other acid proteases

1980 ◽  
Vol 45 (4) ◽  
pp. 1144-1154 ◽  
Author(s):  
Miroslav Baudyš ◽  
Helena Keilová ◽  
Vladimír Kostka
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
The Other ◽  
Terminal Sequence ◽  
Terminal Part ◽  
Terminal Amino Acid ◽  
Tryptic Peptides ◽  
Terminal Amino ◽  
High Degree ◽  
Terminal Amino Acid Sequence

To determine the primary structure of the C-terminal part of the molecule of chicken pepsinogen the tryptic, chymotryptic and thermolytic digest of the protein were investigated and peptides derived from this region were sought. These peptides permitted the following 21-residue C-terminal sequence to be determined: ...Ile-Arg-Glu-Tyr-Tyr-Val-Ile-Phe-Asp-Arg-Ala-Asn-Asn-Lys-Val-Gly-Leu-Ser-Pro-Leu-Ser.COOH. A comparison of this structure with the C-terminal sequential regions of the other acid proteases shows a high degree of homology between chicken pepsinogen and these proteases (e.g., the degree of homology with respect to hog pepsinogen and calf prochymosin is about 66%). Additional tryptic peptides, derived from the N-terminal part of the zymogen molecule whose amino acid sequence has been reported before, were also obtained in this study. This sequence was extended by two residues using an overlapping peptide. An ancillary result of this study was the isolation of tryptic peptides derived from other regions of the zymogen molecule.

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