Primary structure of guinea pig plasma prekallikrein

A full length guinea pig plasma prekallikrein (PK) cDNA was cloned from a l iver cDNA library. The nucleotide sequence with 2242 bp was analyzed and th e amino acid sequence with 618 residues was deduced. Kallikrein was purifie d from guinea pig plasma and cleavage site in the activation was determined . The amino acid sequence around the cleavage site -(368)Ile-Asp-Ala-Arg-Il e-Val-Gly-(375)Gly- differed from that of the human PK -(368)Thr-Ser-Thr-Ar g-Ile-Val-Gly-(375)Gly-. Protease substrates containing penta-peptides whic h mimicked the sequence of the cleavage sites from P-3 to P-2' of guinea pi g Hageman factor (HF) and PK were synthesized, and kinetic analyses of the hydrolysis by guinea pig activated HF (HFa) and kallikrein were carried out . The combination between HFa and the PK mimicking peptide provided the bes t kinetics. These results in part explain why the cascade activation of PK by HFa is predominant in the guinea pig system. (C) 1999 Elsevier Science B .V. All rights reserved.