Amino acid sequence of the Bb fragment from complement Factor B. Sequence of the major cyanogen bromide-cleavage peptide (CB-II) and completion of the sequence of the Bb fragment

The amino acid sequence of peptide CB-II, the major product (mol.wt. 30 000) of CNBr cleavage of fragment Bb from human complement Factor B, is given. The sequence was obtained from peptides derived by trypsin cleavage of peptide CB-II and clostripain digestion of fragment Bb. Cleavage of two Asn-Gly bonds in peptide CB-II was also found useful. These results, along with those presented in the preceding paper [Gagnon & Christie (1983) Biochem. J. 209, 51-60], yield the complete sequence of the 505 amino acid residues of fragment Bb. The C-terminal half of the molecule shows strong homology of sequence with serine proteinases. Factor B has a catalytic chain (fragment Bb) with a molecular weight twice that of proteinases previously described, suggesting that it is a novel type of serine proteinase, probably with a different activation mechanism.

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The principal site of glycation of human complement factor B

Biochemical Journal ◽

10.1042/bj2740473 ◽

1991 ◽

Vol 274 (2) ◽

pp. 473-480 ◽

Cited By ~ 10

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.

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503 A GENETIC CODING VARIANT IN COMPLEMENT FACTOR B IS ASSOCIATED WITH INCREASED RISK FOR PERIANAL CROHN'S DISEASE AND LEADS TO AN AMINO ACID CHANGE IN THE LINKER REGION THAT IMPAIRS CLEAVAGE OF CFB, AND COMPLEMENT-DRIVEN PHAGOCYTOSIS

Gastroenterology ◽

10.1016/s0016-5085(21)00984-7 ◽

2021 ◽

Vol 160 (6) ◽

pp. S-100

Author(s):

Marcy Akhlaghpour ◽

Lisa S. Thomas ◽

Talin Haritunians ◽

Carol Landers ◽

Stephan R. Targan ◽

...

Keyword(s):

Amino Acid ◽

Amino Acid Change ◽

Complement Factor ◽

Factor B ◽

Linker Region ◽

Perianal Crohn’S Disease ◽

Complement Factor B ◽

Genetic Coding ◽

Increased Risk ◽

Perianal Crohn's Disease

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Amino acid sequence of the Bb fragment from human complement Factor B. Alignment of the cyanogen bromide-cleavage peptides

Biochemical Journal ◽

10.1042/bj2090051 ◽

1983 ◽

Vol 209 (1) ◽

pp. 51-60 ◽

Cited By ~ 6

Author(s):

J Gagnon ◽

D L Christie

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Human Factor ◽

Alternative Pathway ◽

Amino Acid Sequences ◽

Complement Factor ◽

Factor B ◽

Arginine Residues ◽

Alternative Pathway Of Complement ◽

Cnbr Cleavage

The alignment of all the CNBr-cleavage peptides of fragment Bb from human Factor B (a component of the alternative pathway of complement) was determined. This was derived from cleavage of the fragment Bb at arginine residues by using trypsin and clostripain. Details of the isolation and amino acid sequences of these peptides are given. Together with previously published N-terminal sequences of the CNBr-cleavage peptides [Christie & Gagnon (1982) Biochem. J. 201, 555-567], this provides the amino acid sequence of the N-terminal half of fragment Bb.

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The amino acid sequence of fragment A, an enzymically active fragment of diphtheria toxin. III. The chymotryptic peptides, the peptides derived by cleavage at tryptophan residues, and the complete sequence of the protein.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)50488-9 ◽

1979 ◽

Vol 254 (13) ◽

pp. 5838-5842

Author(s):

R J DeLange ◽

L C Williams ◽

R E Drazin ◽

R J Collier

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Diphtheria Toxin ◽

Complete Sequence ◽

Tryptophan Residues ◽

Active Fragment

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Plasma protein expression profiles, cardiovascular disease, and religious struggles among South Asians in the MASALA study

Scientific Reports ◽

10.1038/s41598-020-79429-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Long H. Ngo ◽

M. Austin Argentieri ◽

Simon T. Dillon ◽

Blake Victor Kent ◽

Alka M. Kanaya ◽

...

Keyword(s):

Cardiovascular Disease ◽

Plasma Protein ◽

Expression Profiles ◽

South Asians ◽

Predictive Biomarkers ◽

Information Criteria ◽

Blood Protein ◽

Complement Factor ◽

Factor B ◽

Complement Factor B

AbstractBlood protein concentrations are clinically useful, predictive biomarkers of cardiovascular disease (CVD). Despite a higher burden of CVD among U.S. South Asians, no CVD-related proteomics study has been conducted in this sub-population. The aim of this study is to investigate the associations between plasma protein levels and CVD incidence, and to assess the potential influence of religiosity/spirituality (R/S) on significant protein-CVD associations, in South Asians from the MASALA Study. We used a nested case–control design of 50 participants with incident CVD and 50 sex- and age-matched controls. Plasma samples were analyzed by SOMAscan for expression of 1305 proteins. Multivariable logistic regression models and model selection using Akaike Information Criteria were performed on the proteins and clinical covariates, with further effect modification analyses conducted to assess the influence of R/S measures on significant associations between proteins and incident CVD events. We identified 36 proteins that were significantly expressed differentially among CVD cases compared to matched controls. These proteins are involved in immune cell recruitment, atherosclerosis, endothelial cell differentiation, and vascularization. A final multivariable model found three proteins (Contactin-5 [CNTN5], Low affinity immunoglobulin gamma Fc region receptor II-a [FCGR2A], and Complement factor B [CFB]) associated with incident CVD after adjustment for diabetes (AUC = 0.82). Religious struggles that exacerbate the adverse impact of stressful life events, significantly modified the effect of Contactin-5 and Complement factor B on risk of CVD. Our research is this first assessment of the relationship between protein concentrations and risk of CVD in a South Asian sample. Further research is needed to understand patterns of proteomic profiles across diverse ethnic communities, and the influence of resources for resiliency on proteomic signatures and ultimately, risk of CVD.

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