We have analyzed the effect on bond specificity of various isolated members of the mouse kallikrein family of proteins on a synthetic peptide containing the bradykinin sequence. The cleavage pattern shows the selected specificity of these proteases toward the synthetic peptide. The Phe-His bond (positions 11-12) in the synthetic peptide was favorably cleaved by most of the members in this family, including gamma nerve growth factor. On the other hand, the Lys-Arg bond (position 3-4) was found to be susceptible only to gamma-NGF. The combination of these cleavages could result in the degradation of bradykinin in vivo.