Aspergillus nidulans에서 분리된 키틴 탈아세틸화 효소활성에 영향을 미치는 아미노산 잔기 분석 = Analysis of Amino Acid Residues Involved in Activities of Chitin Deacetylase of Aspergillus nidulans

국문 초록 (Abstract)

A. nidulans chitin deacetylase를 자가분해 용액으로부터 소수성 상호작용 컬럼 크로마토그래피와 이온 교환 컬럼 크로마토그래피를 통해 순수 분리하였다. 효소 활성에 관여하는 아미노산을 분석하기 위해 효소 단백질과 특정 아미노산 잔기에 작용하는 화학 수식제를 반응시켜 효소를 화학 수식하였다. histidine 잔기가 화학 수식된 효소는 효소활성을 100% 상실하였으며, arginine의 잔기 혹은 tyrosine 잔기는 100 ${\mu}M$보다 높은 농도의 수식제로 화학수식 되었을 때 효소활성이 감소하였다. Aspartic acid 혹은 glutamic acid의 carboxyl group 잔기의 화학수식은 효소활성의 상대적으로 작은감소를 나타냈다. 이것은 산성 아미노산의 잔기가 화학 촉매 반응에 직접 관여하지 않았거나 혹은 산성 아미노산 잔기는 효소단백질의 전반적인 구조에 영향을 미친다는 것을 추론할 수 있다. 이러한 결과는 효소 단백질의 촉매활성에 histidine, tyrosine 및 arginine 잔기가 중요한 역할을 담당하는 것을 의미한다.

다국어 초록 (Multilingual Abstract)

Native chitin deacetylase of Aspergillus nidulans was purified to apparent homogeneity by a combination of phenyl-Sepharose and Q-Sepharose column chromatography. In order to analyze the amino acid residues involved in the enzyme activity, the enzyme was chemically modified with chemical agent, which selectively reacted with the specific amino acid residue on the protein. When the enzyme was chemically modified with diethylpyrocarbonate, which specifically reacted with histidine residues on the protein, the activity was eliminated. The chitin deacetylase, chemically modified with 100 ${\mu}M$ modifier at the residue of arginine or tyrosine, has shown to have decreased activities. It was shown that the modification at aspartic acid or glutamic acid did not affect the enzyme activity to a greater extent, which would not implicate that acid amino residues were directly involved in catalytic reaction and would affect on the global structures of the proteins. This results demonstrated that histidine and tyrosine residues of enzyme would participate in an important function of the chitin deacetylase activity.

참고문헌 (Reference)

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