Comparison of two type IV hyperthermophilic adenylyl cyclases characterizations from the archaeon Pyrococcus furiosus

摘要

In this paper, two genes that encoded two soluble type IV adenylyl cyclases (AC) from the hyperthermophilic archaeon Pyrococcus furiosus (PFACI and PFACII) were cloned and expressed in Escherichia coli (E. coli) BL21 (DE3). Amino acid sequence analysis of the two enzymes showed 29% homology. PFAC 1 and PFAC II were both Mn~(2+) activated enzyme. They were purified by His-trap chromatography and had a specific activity of 3.1 x 10~3 U/mg at pH 10.0,95 °C (PFAC I) and 2.0 x 10~3 U/mg at pH 11.0,95 °C (PFAC II), respectively. The K_m and k_(cat) of PFAC I was 1.38 mM and 1.11 s~(-1). The K_m and k_(cat) of PFAC II was 1.44 mM and 0.80 s~(-1). The thermostability of PFAC I and PFAC II were higher than the soluble type IV adenylyl cyclases from Yersinia pestis (YpAC-IV). All of the properties suggested that these two adenylyl cyclases may be useful for the industrial producing of cyclic adenosine 3',5'-monophosphate (cAMP).