Kazumasa Takao1,2, Shinji Takai1, Takafumi Ishihara2,
Shiro Mita2 and Mizuo Miyazaki1,*
1Department of Pharmacology, Osaka Medical College, Takatsuki,
Osaka 569 - 8686, Japan
2Discovery Research Division, Santen Pharmaceutical Co., Ltd.,
Ikoma, Nara 630 - 0101, Japan
* To whom correspondence should be addressed.
Abstract: Chymase is a chymotrypsin-like protease localized in
mast cells in complexes with heparin. In the present study, we demonstrated
that suramin, a hexasulfonated naphthylurea used as an anti-cancer drug,
inhibits the activity of purified human chymase in vitro. The inhibition
was ionic-strength-dependent. It was observed that suramin competed with
heparin-Sepharose gel for binding to chymase and the inhibition of chymase
activity by suramin was partially impaired by heparin. Our results show
that suramin may become a prototype of a new type of chymase inhibitor because
of its unique character.
Keywords: Chymase, Suramin, Heparin