Microbiology and Biotechnology Letters (한국미생물·생명공학회지)

The Korean Society for Microbiology and Biotechnology (한국미생물·생명공학회)
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Purification and Properties of an Extracellular Chitinase from Streptomyces sp.

Streptomyces속 균주로 부터 생산되는 Chitinase의 정제 및 그 성질

  • Hong, Yong-Ki (Department of Agricultural Chemistry, Graduate School, Kyungpook National University) ;
  • Seu, Jung-Hwn (Department of Agricultural Chemistry, Graduate School, Kyungpook National University)
  • Published : 1979.09.01
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Abstract

Streptomyces sp. 115-5 was selected as the most active microorganism of about 200 strains for the production of chitinase. The enzyme was purified by (NH$_4$)$_2$SO$_4$ treatment, 1st-Sephadex G-100, DEAE-Cellulose, 2nd-Sephadex G-100 column chromatography, and evidence for homogenity was obtained from CM-Sephadex C-50 column chromatography and polyacylamide gel electrophoresis. The purified enzyme hydrolyzed chitin (N-acetyl glucosamine polymer) and chitosan (glucosamine polymer) but not cellulose. And with chitin as the substrate, a Km value of 3.6 mg of chitin per ml and a Vmax of 100 $\mu$mo1e fer hr were found. The activation of the chitinase was 3.66 kcal per mole. The molecular weight of the enzyme was esti-mated about 56,000 daltons by Sephadex G-100 chromatography and isoelectric point as pH 3.0.

자연계에서 진균류와 절족동물의 외피를 이루는 주된 다당류인 chitin(N-acetyl glucosamine polymer)의 $\beta$-1, 4-lingkage를 가수분해하는 Strepto-myces sp. 115-5 균주로부터 생성되는 chitinase를 정제하여 그 성질을 조사하였다. 48시간 진탕배양하여 생성된 chitinase를 ammonium sulfate처리, 1차 Sephadex G-100, DEAE-Cellulose, 2차 Sephadex G-100 column chromatography하여 정제하였으며 그 순도를 CM-Sephadex C-50 column chromatography 및 polyacryla-mide gel electrophoresis로서 확인하였다. 이 chitinase는 chitin과 chitosan을 가수분해 할수 있었으나 cellulose는 분해할수 없었고 chitin을 기질로서 사용하였을 경우 Km value가 3.6mg/ml이며 Vmax가 100 $\mu$mole/hr였다. Activation energy는 산 가수분해보다 훨씬 낮은 3.66kca1/mole이었고 분자량은 Sephadex G-100을 사용한 column chromatography에서 56,000 daltons으로 나타났으며, 이 chitinase의 등전점은 pH3.0에서 보여졌다.

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