Thioester function is conserved in SpC3, the sea urchin homologue of the complement component C3

被引:0
作者
Smith, LC
机构
[1] George Washington Univ, Dept Biol Sci, Washington, DC 20052 USA
[2] George Washington Univ, Inst Biomed Sci, Washington, DC 20052 USA
关键词
sea urchin; coelomic fluid; complement; autolysis; thioester; echinoderm; opsonization; evolution;
D O I
暂无
中图分类号
S9 [水产、渔业];
学科分类号
0908 ;
摘要
The amino acid sequence of the thioester site in the alpha chain of SpC3, the sea urchin homologue of C3, is conserved. This implies a conserved function of covalent bond formation with amine or hydroxyl groups on target molecules. When coelomic fluid (CF) was incubated with C-14-methylamine, a classic assay for thioester binding function, the alpha chain became labeled. When CF was treated to induce autolysis, peptide bond cleavage occurred at the thioester site. Autolysis could be blocked or reduced by pre-treating CF with either methylamine or yeast, both of which are known to bind to thioester sites 0 proteins from other organisms. The data suggest that SpC3 can bind to target cell surfaces, constituting indirect evidence that it can covalently bind to pathogen surfaces and function as an opsonin in vivo. This activity may be an important aspect of host defense in the sea urchin. (C) 2002 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:603 / 614
页数:12
相关论文
共 60 条
[1]  
Al-Sharif WZ, 1998, J IMMUNOL, V160, P2983
[2]   α2-macroglobulin:: an evolutionarily conserved arm of the innate immune system [J].
Armstrong, PB ;
Quigley, JP .
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY, 1999, 23 (4-5) :375-390
[3]   ELECTROPHORETICALLY SLOW AND FAST FORMS OF THE ALPHA-2-MACROGLOBULIN MOLECULE [J].
BARRETT, AJ ;
BROWN, MA ;
SAYERS, CA .
BIOCHEMICAL JOURNAL, 1979, 181 (02) :401-418
[4]   The role of complement in inflammation and adaptive immunity [J].
Barrington, R ;
Zhang, M ;
Fischer, M ;
Carroll, MC .
IMMUNOLOGICAL REVIEWS, 2001, 180 :5-15
[5]   Innate immunity - Innate pathways that control acquired immunity [J].
Bendelac, A ;
Fearon, DT .
CURRENT OPINION IN IMMUNOLOGY, 1997, 9 (01) :1-3
[6]  
BOTTO M, 1992, J IMMUNOL, V149, P1348
[7]  
CHAN AC, 1984, J IMMUNOL, V132, P1967
[8]   Expression of SpC3, the sea urchin complement component, in response to lipopolysaccharide [J].
Clow, LA ;
Gross, PS ;
Shih, CS ;
Smith, LC .
IMMUNOGENETICS, 2000, 51 (12) :1021-1033
[9]  
CLOW LA, 2001, THESIS GEORGE WASHIN
[10]  
Colten H. R., 1993, COMPLEMENT HLTH DIS, P127, DOI DOI 10.1007/978-94-011-2214-6_4