NEW SYNTHESIS FOR THE PREPARATION OF N-MECAPTOACETYL-(L)-HISTIDINE AND A STUDY OF ITS METAL-COMPLEXES

Two new synthetic routes have been developed for the preparation of N- mercaptoacetil-(L)-histidine (MAH), a compound that can be used as a s imple model for ,,zinc finger'' peptides. Both products were oily. The equilibrium constants of 1:1 complexes of MAH and Co2+, Ni2+, Cu2+, C u+, Zn2+ (log K = 5.64, 6.41, 10.46, 6.17 and 7.55, respectively; t = 25-degrees-C, I = 0.15 M NaCl) were determined by pH/metric titration. The ML2 complexes are insoluble in water.