Z-Leu-Leu-Leu-H, A Neurite Outgrowth Factor Inhibits Brain-Type Creatine Kinase activity

Abstract

Z-Leu-Leu-Leu-H is an exogenous neurite-outgrowth factor.In this paper, we report the isolation and identification of brain-type creatine kinase as a new target protein other than S-100β for Z-Leu-Leu-Leu-H by means of affinity chromatography using the ligand of Z-Leu-Leu-Leu.Protein purification from bovine cerebrum extract was performed by DEAE-5 PW HPLC(stepwise elution or linear gradient elution), reversed phase HPLC.The purified protein of 43 kDa was digested with trypsin and submitted to reversed phase HPLC.Amino acid sequences of obtained two peptides(12-32, 224-233)were identical with brain-type creatine kinase.The enzymatic activity was strongly inhibited by the addition of Z-Leu-Leu-Leu-H.These results suggest that the inhibition of brain-type creatine kinase may induce neurite outgrowth by Z-Leu-Leu-Leu-H.