Complement factor D, a novel serine protease

Protein Sci. 1996 Apr;5(4):553-64. doi: 10.1002/pro.5560050401.

Abstract

Factor D is unique among serine proteases in that it requires neither enzymatic cleavage for expression of proteolytic activity nor inactivation by a serpin for its control. Regulation of factor D activity is instead attained by a novel mechanism that depends on reversible conformational changes for expression and control of catalytic activity. These conformational changes are believed to be induced by the single natural substrate, C3bB, and to result in realignment of the catalytic triad, the specificity pocket, and the nonspecific substrate binding site, all of which have atypical conformations. Mutational studies have defined structural determinants responsible for these unique structural features of factor D and for the resultant low reactivity with synthetic esters.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Complement Factor D / chemistry
  • Complement Factor D / physiology*
  • Crystallography, X-Ray
  • Humans
  • Molecular Sequence Data
  • Protein Conformation
  • Serine Endopeptidases / chemistry
  • Serine Endopeptidases / physiology*
  • Substrate Specificity

Substances

  • Serine Endopeptidases
  • CFD protein, human
  • Complement Factor D