scholarly journals Carbohydrate is linked through ethanolamine to the C-terminal amino acid of Trypanosoma brucei variant surface glycoprotein

1983 ◽  
Vol 209 (1) ◽  
pp. 261-262 ◽  
Author(s):  
A A Holder
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Trypanosoma Brucei ◽  
Carboxy Group ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Side Chain ◽  
Serine Residue ◽  
Terminal Amino Acid ◽  
Terminal Amino

The C-terminal amino acid of the variant surface glycoprotein from Trypanosoma brucei is glycosylated. For two variant proteins that terminate in an aspartic acid and a serine residue respectively, it was shown that the sugar side chain is linked through ethanolamine to the alpha-carboxy group of the amino acid.

scholarly journals Trypanosoma brucei brucei variant surface glycoprotein contains non-N-acetylated glucosamine

1986 ◽  
Vol 234 (2) ◽  
pp. 481-484 ◽  
Author(s):  
A M Strang ◽  
J M Williams ◽  
M A J Ferguson ◽  
A A Holder ◽  
A K Allen
Keyword(s):  
Amino Acid ◽  
Acid Hydrolysis ◽  
Trypanosoma Brucei ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
Amino Group ◽  
Terminal Amino Acid ◽  
Trypanosoma Brucei Brucei ◽  
Parasitic Protozoan ◽  
Terminal Amino

The C-terminal amino acid of the variant surface glycoprotein of the parasitic protozoan Trypanosoma brucei brucei is glycosylated and the oligosaccharide has been shown to contain glucosamine. By acid hydrolysis, HNO2 deamination and 1H-n.m.r. studies we have demonstrated that the amino group of this glucosamine is not N-acetylated and is most probably unmodified.

scholarly journals Factor D̄ of the alternative pathway of human complement. Purification, alignment and N-terminal amino acid sequences of the major cyanogen bromide fragments, and localization of the serine residue at the active site

1980 ◽  
Vol 187 (3) ◽  
pp. 863-874 ◽  
Author(s):  
D M Johnson ◽  
J Gagnon ◽  
K B Reid
Keyword(s):  
Amino Acid ◽  
Sequence Analysis ◽  
Amino Acid Sequence ◽  
Alternative Pathway ◽  
Amino Acid Sequences ◽  
Serine Residue ◽  
Amino Acid Sequence Analysis ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

The serine esterase factor D of the complement system was purified from outdated human plasma with a yield of 20% of the initial haemolytic activity found in serum. This represented an approx. 60 000-fold purification. The final product was homogeneous as judged by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (with an apparent mol.wt. of 24 000), its migration as a single component in a variety of fractionation procedures based on size and charge, and its N-terminal amino-acid-sequence analysis. The N-terminal amino acid sequence of the first 36 residues of the intact molecule was found to be homologous with the N-terminal amino acid sequences of the catalytic chains of other serine esterases. Factor D showed an especially strong homology (greater than 60% identity) with rat ‘group-specific protease’ [Woodbury, Katunuma, Kobayashi, Titani, & Neurath (1978) Biochemistry 17, 811-819] over the first 16 amino acid residues. This similarity is of interest since it is considered that both enzymes may be synthesized in their active, rather than zymogen, forms. The three major CNBr fragments of factor D, which had apparent mol.wts. of 15 800, 6600 and 1700, were purified and then aligned by N-terminal amino acid sequence analysis and amino acid analysis. By using factor D labelled with di-[1,3-14C]isopropylphosphofluoridate it was shown that the CNBr fragment of apparent mol.wt. 6600, which is located in the C-terminal region of factor D, contained the active serine residue. The amino acid sequence around this residue was determined.

scholarly journals Purification and Properties of Staphylocoagulase

1975 ◽  
Author(s):  
A.D. Muller ◽  
B. M. Bas ◽  
H. C. Hemker
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Aspartic Acid ◽  
Acid Composition ◽  
Isoelectric Point ◽  
Terminal Amino Acid ◽  
Purification And Properties ◽  
Terminal Amino

Staphylocoagulase, an exoprotein of coagulase positive staphylocoagulase, has been purified to a state in which only trace amounts of contaminating proteins are detectable.Purification was more than 35,000 fold, which is 7 times more than the highest value reported in the literature. The yield was about 15%.Aspartic acid was found as a single N-terminal amino acid in this preparation. The molecular weight is 61,000 and the isoelectric point lies at pH 4.53.The amino acid composition was determined.

N-terminal amino acid sequences of variant-specific surface antigens from Trypanosoma brucei

Nature ◽  
1976 ◽  
Vol 263 (5578) ◽  
pp. 613-614 ◽  
Author(s):  
PAMELA J. BRIDGEN ◽  
GEORGE A. M. CROSS ◽  
JOHN BRIDGEN
Keyword(s):  
Amino Acid ◽  
Specific Surface ◽  
Trypanosoma Brucei ◽  
Surface Antigens ◽  
Amino Acid Sequences ◽  
Terminal Amino Acid ◽  
Terminal Amino

scholarly journals Locations of the six disulphide bonds in a variant surface glycoprotein (VSG 117) from Trypanosoma brucei

1983 ◽  
Vol 209 (2) ◽  
pp. 481-487 ◽  
Author(s):  
G Allen ◽  
L P Gurnett
Keyword(s):  
Amino Acid ◽  
Trypanosoma Brucei ◽  
Thiol Group ◽  
Cysteine Residue ◽  
Terminal Region ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
British Library ◽  
African Trypanosome ◽  
Disulphide Bonds

The locations of the six disulphide bonds and the single free cysteine residue in a variant surface glycoprotein, VSG 117, from the African trypanosome Trypanosoma brucei have been determined to be Cys-14-Cys-140, Cys-121-Cys-182, Cys-389-Cys-404, Cys-398-417, Cys-447-Cys-461 and Cys-455-Cys-468. Cys-244 bears the single thiol group, which is unreactive towards 2-nitro-5-thiocyanobenzoate in the native molecule and is probably buried. Biosynthetically incorporated [35S]cysteine aided the location of the disulphide bonds. Two proteinase-resistant glycosylated domains, each containing two disulphide bonds, were identified in the C-terminal region of the glycoprotein. Details of purification of [35S]cysteine-containing peptides, and Tables of amino acid analyses, are presented in Supplementary Publication SUP 50119 (32 pages), which has been deposited with the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1981) 193,5.

CONCERNING THE NATURE OF THE α- AND β-LYTIC PROTEASES OF SORANGIUM SP.

1967 ◽  
Vol 45 (6) ◽  
pp. 911-916 ◽  
Author(s):  
D. R. Whitaker ◽  
C. Roy
Keyword(s):  
Amino Acid ◽  
Serine Protease ◽  
Lytic Enzyme ◽  
Serine Residue ◽  
Terminal Amino Acid ◽  
Electrophoretic Patterns ◽  
Diisopropyl Phosphorofluoridate ◽  
Terminal Amino ◽  
Inhibited Enzyme ◽  
Serine Phosphate

The α-lytic protease is readily inhibited by diisopropyl phosphorofluoridate (DFP) and the yield of serine phosphate from acid-hydrolyzed, DFP-inhibited enzyme indicates that DFP esterifies one serine residue of the enzyme. Acid digests of enzyme treated with isopropyl methylphosphonofluoridate-32P (sarin) show much the same electrophoretic patterns of 32P-labelled peptides as similar digests of sarin-treated trypsin and chymotrypsin; amino acid analyses and N-terminal amino acid analyses of peptides isolated from the digest confirm that the α-enzyme has the same sequence (Asp-Ser*-Gly-Gly) around the reactive serine residue as the pancreatic enzymes. At present, the α-enzyme is the only microbial "serine protease" which is known to have this sequence. It is also unique as a serine protease in that it has only one histidine residue.The β-lytic enzyme is not inhibited by DFP and shows no evidence of reactivity towards sarin. Its zinc atom can be removed by o-phenanthroline without loss of lytic activity. At present, it cannot be classed in any of the major groups of proteases.

scholarly journals A new method for the rapid purification of both the membrane-bound and released forms of the variant surface glycoprotein from Trypanosoma brucei

1985 ◽  
Vol 230 (1) ◽  
pp. 195-202 ◽  
Author(s):  
D G Jackson ◽  
M J Owen ◽  
H P Voorheis
Keyword(s):  
Amino Acid ◽  
Trypanosoma Brucei ◽  
Aqueous Salt Solution ◽  
Surface Glycoprotein ◽  
Variant Surface Glycoprotein ◽  
High Yield ◽  
Dependent Manner ◽  
Wide Range ◽  
Membrane Bound ◽  
Rapid Purification

A simple new technique was developed for the rapid purification of either the membrane-bound or the released forms of the variant surface glycoprotein of Trypanosoma brucei in high yield. Whole cells were used as the source of the membrane-bound form, and the supernatant of benzyl alcohol-treated cells was used as the source of the released form. The technique was based on extraction of the acid-treated protein into chloroform/methanol, followed by selective re-partition into aqueous salt solution. The yield of purified protein was found to be dependent critically on a low pH during the extraction/re-partition stages. This finding and the ability to cycle the protein repeatedly through organic and aqueous phases in a strictly pH-dependent manner suggested that the protein could undergo fully reversible denaturation/renaturation only while in an extensively protonated form. The yield was independent of the polarity of the organic phase and the protein concentration over a wide range. After purification, both forms retain their ability to react with specific antibody raised against the authentic native protein purified by conventional means. The amino acid composition and the identity of the N-terminal amino acid was the same for both forms of the protein. In addition, both forms had blocked C-terminal residues. There were determined to be 1.13 × 10(7) copies of the variant surface glycoprotein per cell.

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