Figure 1.

ClustalW alignment of human, porcine, rat, and mouse chymotrypsin C (CTRC) proteins. Chymotrypsin C (encoded by CTRC) contains 8 exons and is located on chromosomes 5q36 (rats) and 1p36.21 (humans). Human and mouse CTRC is 80% homologous, whereas human CTRC and KLK4 protein sequences share ~30% homology. In humans, CTRC is a secreted protein synthesized as a preproenzyme of 268 amino acids, with a signal peptide of 16 amino acids and an activation peptide of 13 amino acids (Tomomura et al., 1995).