Structure, Function and Mechanism of a Protease 

Prostate specific antigen (PSA), a serine protease produced by the prostate, has been extensively used as marker for prostate cancer. It has chymorypsin-type specificity toward its physiologic substrates, semenogelin I and II. PSA has also been implicated in growth regulation because it cleaves IGFBP3 and PTHrp, which are proteins associated with cellular growth regulation; prostate and breast cancer metastasis, respectively. The goal of this project is to understand the regulation and molecular basis of PSA in the development of prostate cancer. Currently, Professor Yang’s group is interested in optimization of the expression of PSA protein in E. coli which will be used to study the mechanistic property of PSA as a protease. The results also have implications for drug design against prostate cancer.