Homologous and heterologous interactions between catalytic and regulatory subunits of Escherichia coli acetohydroxyacid synthaseⅠand Ⅲ  

作　　者：NIU CongWei, FENG Wei, ZHOU YanFei, WEN Xin & XI Zhen State Key Laboratory of Elemento-Organic Chemistry and Department of Chemical Biology, Nankai University, Tianjin 300071, China 

出　　处：《Science China Chemistry》2009年第9期1362-1371,共10页中国科学（化学英文版）

基　　金：Supported by the National Key Project for Basic Research of China (Grant No. 2010CB126102);National Natural Science Foundation of China (Grant Nos. 20572053, 20421202 & 20432010);Ministry of Education of China (Grant No. 104189)

摘　　要：Homologous and heterologous interactions between acetohydroxyacid synthase (AHAS) I and Ⅲ from E. coli have been studied by surface plasmon resonance (SPR). The catalytic and regulatory subunits association for AHAS I (KD = 1.13 × 10-7 M) was stronger than that for AHAS Ⅲ (KD = 5.29 × 10-7 M). A strong heterologous association between regulatory and catalytic subunits and heterologous activation of catalytic subunits were observed. SPR results combined with enzyme kinetics indicate that the reconstituted heterologous enzymes had similar kinetic properties as homologous enzymes, implying that the regulatory subunit of AHAS I could be replaced by the regulatory subunit of AHAS Ⅲ and vice versa. This work may be useful to further understandings of the mechanism of regulation of AHAS.Homologous and heterologous interactions between acetohydroxyacid synthase (AHAS) I and Ⅲ from E. coli have been studied by surface plasmon resonance (SPR). The catalytic and regulatory subunits association for AHAS I (KD = 1.13 × 10-7 M) was stronger than that for AHAS Ⅲ (KD = 5.29 × 10-7 M). A strong heterologous association between regulatory and catalytic subunits and heterologous activation of catalytic subunits were observed. SPR results combined with enzyme kinetics indicate that the reconstituted heterologous enzymes had similar kinetic properties as homologous enzymes, implying that the regulatory subunit of AHAS I could be replaced by the regulatory subunit of AHAS Ⅲ and vice versa. This work may be useful to further understandings of the mechanism of regulation of AHAS.

关 键 词：acetohydroxyacid SYNTHASE SUBUNIT interaction surface PLASMON resonance 

分 类 号：O621.3[理学—有机化学]