Purification and enzymatic characteristics of cysteine desulfurase,IscS,in Acidithiobacillus ferroox

• 作 者: 吴安娜 张燕飞 郑春丽 戴云杰 刘元东 曾嘉 顾帼华 柳建设
• 机 构: Key Laboratory of Biometallurgy of Ministry of Education,School of Minerals Processing and Bioengine
• 出 处: Transactions of Nonferrous Metals Society of China
• 发表日期: 2008年06期
• 关键词: cysteine affinity cloned inhibited Plasmid enzymatic purified assembly visible s

A cysteine desulfurase protein,IscS,was encoded by the operon iscSUA in Acidithiobacillus ferrooxidans.The gene of IscS from Acidithiobacillus ferrooxidans ATCC 23270 was cloned and expressed in Escherichia coli.The protein was purified by one-step affinity chromatography to homogeneity.The final protein yield after affinity chromatography was 12.9%.The enzyme was characterized for thermal stability,pH and kinetic parameters.The molecular mass of recombinant IscS was 46 ku by SDS-PAGE. The optimum pH was 8.0-8.5.The enzyme had a temperature optimum at 30℃and was relatively stable at 40℃,with 67% loss of activity.1,5-I-AEDANS significantly inhibited IscS activity.Kinetic parameters K_m and V_(max)were found to be 0.11 mmol/L and 2.57μmol/(L·min).

A cysteine ​​desulfurase protein, IscS, was encoded by the operon iscSUA in Acidithiobacillus ferrooxidans. The gene of IscS from Acidithiobacillus ferrooxidans ATCC 23270 was cloned and expressed in Escherichia coli. The protein was purified by one-step affinity chromatography to homogeneity.The final protein yield after affinity chromatography was 12.9%. The enzyme was characterized for thermal stability, pH and kinetic parameters. The molecular mass of recombinant IscS was 46 ku by SDS-PAGE. The optimum pH was 8.0-8.5. The enzyme had a temperature optimum at 30 ° C and was relatively stable at 40 ° C with 67% loss of activity.1,5-I-AEDANS significantly enhanced IscS activity. Kinetic parameters Km and Vmax were found to be 0.11 mmol / L and 2.57 μmol / ( L · min).