α-葡萄糖苷酶抑制劑由於其在治療糖尿病中的重要用途而受到重視。雖然一些合成的 α-葡萄糖苷酶抑制劑已經可以使用很長時間,但是它們經常會引起各種的副作用。因此,本研究旨在找到一種安全,天然的 α-葡萄糖苷酶抑制劑來源。本實驗利用篩選自淡江大學校園之菌株Staphylococcus sp. TKU 043,發酵蝦頭殼粉生產α-葡萄糖苷酶抑制劑。於含1%蝦頭殼粉培養基培養 3 天,可得較佳α-葡萄糖苷酶抑制活性(1457U / mL)。所得發酵上清液經硫酸銨鹽沉澱、DEAE-Sepharose陰離子交換管柱層析、Sepharcryl-S200膠體管柱層析,進行α-葡萄糖苷酶抑制劑之部份純化。此抑制劑於50℃處理30 分鐘後活性僅存20%,在pH 3-7反應皆具100 %之抑制活性。 依據研究結果顯示,TKU 043所生產之α-葡萄糖苷酶抑制劑為大分子化合物,推測此抑制劑可能為蛋白質類或是胜肽類化合物;利用酵素抑制動力學鑑定出此抑制劑為混合型(非競爭)抑制劑。
Alpha-glucosidase inhibitors have received much attention due to their important use in treating diabetes mellitus. Although some synthetic α-glucosidase inhibitors have been available for a long time, they often cause various unexpected side effects. Thus, the present study was aimed at finding a safe, natural source of α-glucosidase inhibitors. Staphylococcus sp. TKU043, a bacterium strain isolated from the soils of Tamkang University Campus, produced alpha-glucosidase inhibitors (1457 U/mL) in a medium with 1% (w/v) shrimp head powder as the sole carbon/nitrogen source. The culture supernatant obtained by culturing under optimized culture condition was purified by ammonium sulfate precipitation, DEAE-Sepharose column chromatography, and Sephacryl S-200 gel chromatography. The partially purified inhibitors remained 20 % original activity after treatment at 50℃ for 30 min. Activity of the alpha-glucosidase inhibitors remained 100 % after treatment at pH 3-7. According to the results of this study, the α-glucosidase inhibitor produced by TKU043 is a proteinous material. The inhibitor is identified as a mixed type (non-competitive) inhibitor according to the results of enzyme inhibition kinetics.