Production and Characterization of an Anti-Angiogenic Agent front Saccharomyces cerevisiae K-7

Abstract

The cell-free extracts of 250 yeasts were screened for their in vitro anti-angiogenic activity, to develop a new cancer metastasis inhibitor. Saccharomyces cerevisiae K-7 was selected as the producer of the anti-angiogenic agent, because it had the highest anti-angiogenic activity. The anti-angiogenic agent was produced maximally from hydrolysates of Saccharomyces cerevisiae K-7, when the yeast was cultured in yeast extract-peptone-dextrose medium at 30°C for 24 h, and cell-free extracts were than digested with pepsin for 4 h at 37°C. The anti-angiogenic agent was further purified by ultrafiltration, Sephadex G-25 gel permeation chromatography and reverse-phase HPLC, and the anti-angiogenic activity of the final purified preparation was 72.7% at 10 μM/egg. The purified anti-angiogenic agent was found to originate from the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) molecule of Saccharomyces cerevisiae K-7, and its peptide sequence was Val-Ser-Trp-Tyr-Asp-Asn-Glu-Tyr-Gly-Tyr-Ser-Thr-Arg-Val-Val-Asp. In the MTT assay, the shape of the HT-1080 cell was clearly changed to a circular type at 0.2 mM purified anti-angiogenic agent. This result indicated that the growth of the HT-1080 cell was significantly inhibited at 0.2 mM of the purified anti-angiogenic agent. The MMP activity of the treated HT-1080 cells was not affected, evidenced by the gelatin zymography, indicating that the anti-angiogenic mechanism of the purified anti-angiogenic agent is not mediated through MMP activity.