Purified protein C from patient plasma was reduced and carboxyamidomethylated and the resulting heavy and light chains were separated by RP-HPLC. An aliquot of the fraction containing the light chain(s) was analyzed by sequence analysis of the first 10 residues. Two parallel sequences were seen in equal amounts as judged from the similar yields of amino acids obtained at comparable residue number positions. One sequence was identical with the normal protein C light chain and the other was the same but N-terminal extended with His. Values given are the yields obtained in the individual cycle corrected for background levels and lag in the following cycle.

No PTH-Glu derivatives could be detected at these residues, indicating that these sites were γ-carboxylated.