Biochemical and Biophysical Research Communications, 2013, 01, 765─771

S1 pocket of glutamate carboxypeptidase II: A new binding site for amyloid-b degradation

SukKyung Lee, Hyunyoung Kim, You-Hoon Cheong, Min-Ju Kim, Sangmee Ahn Jo, Hyung-Seop Youn, Sang Ick Park

Abstract

We recently reported that glutamate carboxypeptidase II (GCPII) has a new physiological function degrading amyloid-b (Ab), distinct from its own hydrolysis activity in N-acetyl-L-aspartyl-L-glutamate (NAAG); however, its underlying mechanism remains undiscovered. Using site-directed mutagenesis and S1 pocket-specific chemical inhibitor (compound 2), which was developed for the present study based on in sillico computational modeling, we discovered that the Ab degradation occurs through S1 pocket but not through S10 pocket responsible for NAAG hydrolysis. Treatment with compound 2 prevented GCPII from Ab degradation without any impairment in NAAG hydrolysis. Likewise, 2-PMPA (specific GCPII inhibitor developed targeting S10 pocket) completely blocked the NAAG hydrolysis without any effect on Ab degradation. Pre-incubation with NAAG and Ab did not affect Ab degradation and NAAG hydrolysis, respectively. These data suggest that GCPII has two distinctive binding sites for two different substrates and that Ab degradation occurs through binding to S1 pocket of GCPII.

• ISBN or ISSN: 0006-291x

• 본 연구는 질병관리본부 연구개발과제(과제번호 2011-N62001-00) 연구비를 지원받아 수행되었습니다.
• This research was supported by a fund(code 2011-N62001-00) by Research of Korea Centers for Disease Control and Prevention.