摘要
P28，a 28kD protein from toad (Bufo bufo gargarizans)oocytes,was identified by using P13^suc1-agarose affinity chromatography.Sequence homology analysis of the full-length cDNA of P28(Gene Bank accession number:AF 314091)indicated that it encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70%positives to encodes a protein containing 224 amino-acids with about 55% iden-tities and more than 70% positives to human, rat or mouse UCH-L1,and contains homological functional domains of UCH family.Anti-p28 monoclonal antibody,on injecting into the oocytes,could inhibit the progesterone-induced resumption of meiotic division in a dose-dependent manner.The recombinant protein P28 showed similar SDS/PAGE behaviors to the native one,and promoted ubiquitin ethyl ester hydrolysis,a classical catalytic reaction for ubiquitin carboxyl terminal hydrolases(UCHs).The results in this paper reveal that a novel protein,p28 ,exists in the toad oocytes,is a UCH Ll homolog,was engaged in the process of progesterone-induced oocyte maturation possibly through an involvement in protein turnover and degradation.
