1. Ribonucleases with antitumor activity are mainly found in the oocytes and embryos of Rana catesbeiana (bullfrog), but the mechanism of antitumor activity and their roles in frog development are not clear. The residues involved in catalytic activity base recognition and cytotoxicity are investigated by site-directed mutagenesis, NMR and X-ray cocrystallography.
2. Antimicrobial peptides/proteins (AMPs) are important components ofthe host innate defense mechanisms against invading microorganisms.The human ribonuclease 7(hRNase 7) possesses membrane permeability and antimicrobial activity through the flexible and clustered lysine residues near N-terminus. In addition to hRNase 7, hundreds of AMPs also exert similar antimicrobial activity. The susceptibility of Gram negative bacteria to these AMPs is determined by an outer membrane protein, like the OprI of Pseudomonas aeruginosa and Lpp of E. coli. Therefore, OprI and its homologues may be used as ligands for the screening and production of antimicrobial materials.
3. The removal of N-terminal Met is often crucial for the function and stability of recombinant proteins. We engineer an E. coli methionine aminopeptidase (MetAP) which is able to remove N-terminal Met from bulky or acidic penultimate residues.
1. 牛蛙之RNA 水解酵素群具抗癌特性，本實驗室以基因突變，核磁共振及X光繞射法，研究其抗癌機制及生化特性。
2. RNA 水解酵素及陽離子抗菌胜肽扮演宿主防禦重要的角色，本實驗室發現其參與破壞細菌外膜的胺基酸，進而找到其在細菌外膜之標的蛋白質，藉此研究抗菌機轉及篩選抗菌胜肽，以克服抗藥菌株產生的問題。