... ECM and BM. Both Zn2+ and free sulfhydryls may be required for LBP binding site onlaminin a s e videnced by the stimulatory and inhibitoryeffects of ZnCl2 and N-ethylmaleimide, respectively. ... indicated the presence of His and Cys at the binding site. However, t he un altered binding parametersafter diethyl pyrocarbonate treatment preclude the possi-bility of the pre sence of His at the ... Preincubation of LBP with either Zn2+or EDTA (Fig. 3C) did not alter the binding activitysuggesting thereby that the cofactor requirement of Zn2+isfor laminin only. Treatment of l aminin with diethylpyrocarbonate,...