Chymotrypsinogen B1 (CTRB1)

Alpha-chymotrypsin is one of a family of serine proteases secreted into the gastrointestinal tract as the inactive precursor chymotrypsinogen. The zymogen is activated by proteolytic cleavage by trypsin (PRSS1). Homology indicates that CTRB is on 16q because it is one of 7 genes that are on 16 in man and on chromosome 8 in the mouse; the other 6 are on 16q, whereas human 16p, which carries the alpha-globin gene cluster, appears to be homologous to mouse 11.The coding region contains 789 bp. The predicted product consisted of 263 amino acids, including 18 amino acids for a signal peptide. Southern blot analyses using the cloned cDNA as a probe showed that human genomic DNA carries at least 2 genes that are related to chymotrypsinogen.