title: Partial amino acid sequence of human factor D:homology with serine proteases.
abstract: Human factor D purified to homogeneity by a modified procedure was subjected to NH2-terminal amino acid sequence analysis by using a modified automated Beckman sequencer. We identified 48 of the first 57 NH2-terminal amino acids in a single sequencer run, using microgram quantities of factor D. The deduced amino acid sequence represents approximately 25% of the primary structure of factor D. This extended NH2-terminal amino acid sequence of factor D was compared to that of other trypsin-related serine proteases. By visual inspection, strong homologies (33--50% identity) were observed with all the serine proteases included in the comparison. Interestingly, factor D showed a higher degree of homology to serine proteases of pancreatic origin than to those of serum origin.
mesh_terms: D000595:Amino Acid Sequence; D001322:Autoanalysis; D001665:Binding Sites; D003166:Complement Activating Enzymes; D011416:Complement Factor D; D006801:Humans; D010447:Peptide Hydrolases; D012694:Serine; D013917:Thrombin; D014357:Trypsin
chemical_list: D012694:Serine; D003166:Complement Activating Enzymes; D010447:Peptide Hydrolases; D014357:Trypsin; C493488:CFD protein, human; D011416:Complement Factor D; D013917:Thrombin