Hideo Yoshizaki

Proteose peptone enhances production of tissue-type plasminogen activator from human diploid fibroblasts

Proteose peptone markedly enhanced the production of human tissue-type plasminogen activator (t-PA) from confluently cultured cell of human diploid fibroblasts. The cells continued synthesizing and secreting high levels of t-PA under periodic replacement of medium containing proteose peptone for more than one month. The highly increased activity correlated with equally increased levels of t-PA antigen and concomitantly increased levels of t-PA specific mRNA.

Protein C activation by recombinant thrombomodulin in plasma

Recombinant glycosaminoglycan-modified urinary thrombomodulin (GAG-UTM), which partially improved the amino acid sequence of human urinary thrombomodulin (UTM), was expressed in C127 cells. GAG-UTM accelerates protein C activation by thrombin and also thrombin inhibition by antithrombin III (ATIII) in the buffer system. Both accelerating activities of GAG-UTM are more potent than those of unmodified recombinant UTM (r-UTM) without a GAG chain. As ATIII in plasma also inhibits protein C activation by a thrombin-thrombomodulin complex, we studied whether GAG-UTM accelerates protein C activation in plasma. GAG-UTM suppressed the generation of thrombin in activating plasma protein C stronger than r-UTM. By Western blot analysis using anti-protein C antibody, activated protein C was generated by GAG-UTM more than by r-UTM. From these results, the acceleration of activated protein C formation by GAG-UTM was confirmed in plasma too.