Sandbox 30: Difference between revisions

Serine proteases cleave using what is commonly called a catalytic triad. This catalytic triad consists of Asp 102, His 57, and Ser 195<ref>Polgár L. "The catalytic triad of serine peptidases". Cell. Mol. Life Sci. October 2005. 62 (19-20): 2161–72.  [http://www.springerlink.com/content/l3t068x156682u55/ doi:10.1007/s00018-005-5160-x]</ref>.  The cleavage mechanism is shown to the left. First, the substrate binds to trypsin, and then the side chain oxygen of Ser 195 nucleophilicly attacks, with assist from His 57. Next, the peptide bond is cleaved, with His 57 assisting again with stabilization.  After cleavage, the first product is released.  Next there is a nucleophilic attack of H20 on the acyl-enzye intermediate (assistance of His 57). This is followed by the decomposition of the acyl intermediate and release of the second product<ref>Polgár L. "The catalytic triad of serine peptidases". Cell. Mol. Life Sci. October 2005. 62 (19-20): 2161–72.  [http://www.springerlink.com/content/l3t068x156682u55/ doi:10.1007/s00018-005-5160-x]</ref>. <applet scene='Sandbox_30/Big_trypsin_rainbow/1' size='300' frame='true' align='right' caption='Bovine trypsin in complex with UB-THR 10' /> You are able to view the <scene name='Sandbox_30/Active_site/1'>actual binding site</scene>. Additionally, you may see the <scene name='Sandbox_30/Active_site/2'>substrate in the binding site</scene>.