Lam SK, Ng TB. A dimeric high-molecular-weight chymotrypsin inhibitor with antitumor and HIV-1 reverse transcriptase inhibitory activities from seeds of Acacia confusa.
PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2010;
17:621-625. [PMID:
19962287 DOI:
10.1016/j.phymed.2009.10.005]
[Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 09/01/2009] [Accepted: 10/12/2009] [Indexed: 05/28/2023]
Abstract
A dimeric 70-kDa chymotrypsin inhibitor with substantial N-terminal sequence homology to serine protease inhibitors was isolated from Acacia confusa seeds. The chymotrypsin inhibitor was purified using a protocol that entailed ion exchange chromatography on Q-Sepharose, SP-Sepharose and fast protein liquid chromatography-gel filtration on Superdex 75. The chymotrypsin inhibitor was unadsorbed on both Q-Sepharose and SP-Sepharose. Its chymotrypsin inhibitory activity was stable from pH 3 to 10 and from 0 to 50 degrees C. It exerted antiproliferative activity toward breast cancer MCF-7 cells with an IC(50) of 10.7+/-4.2 microM. It inhibited HIV-1 reverse transcriptase with an IC(50) of 8+/-1.5 microM. It was devoid of antifungal activity toward a variety of fungal species. The distinctive features of the chymotrypsin inhibitor included dimeric nature, a high molecular mass, lack of trypsin inhibitory activity, highly potent HIV-1 reverse transcriptase inhibitory activity, specific antitumor activity and relatively high pH-stability.
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