鳥胺酸異構酶特性之探討

Characterization of D-ornithine aminomutase

楊文學(Wun-Syue Yang)

指導教授 ： 陳灝平

國立臺北科技大學/工程學院/生物科技研究所/碩士(2006年)

摘要

Clostridium sticklandii 此菌株內的鳥胺酸異構酶(D-ornithine aminomutase)可將D-ornithine 催化成(2R，4R)-2，4-diaminopentanoic acid。鳥胺酸異位酶由兩個次單元所組成，分別為OraS及OraE。OraS由121個胺基酸組成，分子量為12800 Da;OraE 由753個胺基酸所組成，分子量為82900 Da。前人研究結果顯示，OraE 蛋白單獨表現時，是以包涵體形式存在。本論文首先找到重新摺疊OraE 蛋白的條件，並針對D-ornithine aminomutase 的活性，討論OraS次單元在催化上扮演的角色。另外，本論文亦發現OraE及OraSE在部分金屬離子存在時，具有蛋白質水解酶活性，本論文也針對此活性，做了初步的探討。

關鍵字

包涵體 ； 重新折疊

並列摘要

D-Ornithine aminomutase from Clostridium sticklandii catalyzes the 1,2-rearrangement reaction of D-ornithine to (2R,4S)-2,4-diaminopentanoic acid. D-Ornithine aminomutase comprised two subunits. the oraS gene, which encodes a protein of 121 amino acid residues with Mr. 12,800, and oraE gene, which encodes a protein of 753 amino acid residues with Mr. 82,900. According to previus studies, OraE was expressed as inclusion bodies when E.coli was used as expression host. The refolding condition of OraE protein was first established in the dissertation. The role of OraS protein during catalysis was also investigated. Finally, our experimental results show that OraE protein possesses metal dependent proteolytic activity. This novel activity was preliminarily characterized.

並列關鍵字

Inclusion bodies ； refolding

參考文獻

2. H. A. Barker, Ann. Rev. Biochem.. Vol.50, 1981, pp.23-40.

8. V. Daggett, Curr. Opin. Biotechnol., Vol.9, 1998, pp.157-163.

10. J. Michael north, Microbiol. Rev, 1982, pp.308-340.

15. C. K. Garrison, R. H. Himes, Biochem. Biophys. Res. Commun. Vol.67, 1975, pp.1251-1255.

參考文獻