Methionine modification impairs the C5-cleavage function of cobra venom factor-dependent C3/C5 convertase

Qinglan Fu, Peter McPhie, Channe Gowda

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The complement-mediated lysis of guinea pig erythrocytes by cobra venom factor (CVF) decreased by 50-60% within 2 min of treatment with 5 mM sodium periodate at 0°C. This loss of activity paralleled modification of 3-4 Met; other amino acids and sugar residues of the oligosaccharide chains were not affected. Treatment with N-chlorosuccinimide or chloramine-T under conditions that specifically modified 3-4 readily-oxidizable Met also caused 50-60% loss of CVF activity. The secondary structure of CVF was not altered by these modifications. Methionine-modified CVF (MetCVF) supported the cleavage of factor B by factor D with equal efficiency as that of untreated CVF to form C3/C5 convertase (MetCVF,Bb) of the alternative pathway. MetCVF,Bb and CVF,Bb were indistinguishable with respect to C3 cleavage. However, the C5-cleavage ability of MetCVF,Bb was significantly lower than that of CVF,Bb. These results suggest the involvement of Met in CVF binding of C5.

Original languageEnglish (US)
Pages (from-to)133-144
Number of pages12
JournalBiochemistry and Molecular Biology International
Volume45
Issue number1
StatePublished - Jun 1998

Fingerprint

Complement C3-C5 Convertases
Methionine
Complement Factor D
Amino Sugars
Complement Factor B
cobra venom factor
Oligosaccharides
Guinea Pigs
Erythrocytes
Amino Acids

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Genetics
  • Molecular Biology

Cite this

@article{45da6612c3774a6982fe3ffa0ff4879c,
title = "Methionine modification impairs the C5-cleavage function of cobra venom factor-dependent C3/C5 convertase",
abstract = "The complement-mediated lysis of guinea pig erythrocytes by cobra venom factor (CVF) decreased by 50-60{\%} within 2 min of treatment with 5 mM sodium periodate at 0°C. This loss of activity paralleled modification of 3-4 Met; other amino acids and sugar residues of the oligosaccharide chains were not affected. Treatment with N-chlorosuccinimide or chloramine-T under conditions that specifically modified 3-4 readily-oxidizable Met also caused 50-60{\%} loss of CVF activity. The secondary structure of CVF was not altered by these modifications. Methionine-modified CVF (MetCVF) supported the cleavage of factor B by factor D with equal efficiency as that of untreated CVF to form C3/C5 convertase (MetCVF,Bb) of the alternative pathway. MetCVF,Bb and CVF,Bb were indistinguishable with respect to C3 cleavage. However, the C5-cleavage ability of MetCVF,Bb was significantly lower than that of CVF,Bb. These results suggest the involvement of Met in CVF binding of C5.",
author = "Qinglan Fu and Peter McPhie and Channe Gowda",
year = "1998",
month = "6",
language = "English (US)",
volume = "45",
pages = "133--144",
journal = "IUBMB Life",
issn = "1521-6543",
publisher = "Wiley-Blackwell",
number = "1",

}

Methionine modification impairs the C5-cleavage function of cobra venom factor-dependent C3/C5 convertase. / Fu, Qinglan; McPhie, Peter; Gowda, Channe.

In: Biochemistry and Molecular Biology International, Vol. 45, No. 1, 06.1998, p. 133-144.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Methionine modification impairs the C5-cleavage function of cobra venom factor-dependent C3/C5 convertase

AU - Fu, Qinglan

AU - McPhie, Peter

AU - Gowda, Channe

PY - 1998/6

Y1 - 1998/6

N2 - The complement-mediated lysis of guinea pig erythrocytes by cobra venom factor (CVF) decreased by 50-60% within 2 min of treatment with 5 mM sodium periodate at 0°C. This loss of activity paralleled modification of 3-4 Met; other amino acids and sugar residues of the oligosaccharide chains were not affected. Treatment with N-chlorosuccinimide or chloramine-T under conditions that specifically modified 3-4 readily-oxidizable Met also caused 50-60% loss of CVF activity. The secondary structure of CVF was not altered by these modifications. Methionine-modified CVF (MetCVF) supported the cleavage of factor B by factor D with equal efficiency as that of untreated CVF to form C3/C5 convertase (MetCVF,Bb) of the alternative pathway. MetCVF,Bb and CVF,Bb were indistinguishable with respect to C3 cleavage. However, the C5-cleavage ability of MetCVF,Bb was significantly lower than that of CVF,Bb. These results suggest the involvement of Met in CVF binding of C5.

AB - The complement-mediated lysis of guinea pig erythrocytes by cobra venom factor (CVF) decreased by 50-60% within 2 min of treatment with 5 mM sodium periodate at 0°C. This loss of activity paralleled modification of 3-4 Met; other amino acids and sugar residues of the oligosaccharide chains were not affected. Treatment with N-chlorosuccinimide or chloramine-T under conditions that specifically modified 3-4 readily-oxidizable Met also caused 50-60% loss of CVF activity. The secondary structure of CVF was not altered by these modifications. Methionine-modified CVF (MetCVF) supported the cleavage of factor B by factor D with equal efficiency as that of untreated CVF to form C3/C5 convertase (MetCVF,Bb) of the alternative pathway. MetCVF,Bb and CVF,Bb were indistinguishable with respect to C3 cleavage. However, the C5-cleavage ability of MetCVF,Bb was significantly lower than that of CVF,Bb. These results suggest the involvement of Met in CVF binding of C5.

UR - http://www.scopus.com/inward/record.url?scp=0031840057&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031840057&partnerID=8YFLogxK

M3 - Article

C2 - 9635137

AN - SCOPUS:0031840057

VL - 45

SP - 133

EP - 144

JO - IUBMB Life

JF - IUBMB Life

SN - 1521-6543

IS - 1

ER -