Quantitative target analysis and kinetic profiling of acyl-CoAs reveal the rate-limiting step in cyanobacterial 1-butanol production
메타 데이터
바이오화학분류
바이오정밀화학
용매
화학제품
연료
화장품용 기능성소재
계면활성제⁄증점제
논문
Quantitative target analysis and kinetic profiling of acyl-CoAs reveal the rate-limiting step in cyanobacterial 1-butanol production
학술지
Metabolomics : official journal of the Metabolomics Society
저자명
Noguchi, Shingo; Putri, Sastia P.; Lan, Ethan I.; Laviñ a, Walter A.; Dempo, Yudai; Bamba, Takeshi; Liao, James C.; Fukusaki, Eiichiro
초록
<P>Cyanobacterial 1-butanol production is an important model system for direct conversion of CO<SUB>2</SUB> to fuels and chemicals. Metabolically-engineered cyanobacteria introduced with a heterologous Coenzyme A (CoA)-dependent pathway modified from <I>Clostridium</I> species can convert atmospheric CO<SUB>2</SUB> into 1-butanol. Efforts to optimize the 1-butanol pathway in <I>Synechococcus elongatus</I> PCC 7942 have focused on the improvement of the CoA-dependent pathway thus, probing the in vivo metabolic state of the CoA-dependent pathway is essential for identifying its limiting steps. In this study, we performed quantitative target analysis and kinetic profiling of acyl-CoAs in the CoA-dependent pathway by reversed phase ion-pair liquid chromatography-triple quadrupole mass spectrometry. Using <SUP>13</SUP>C-labelled cyanobacterial cell extract as internal standard, measurement of the intracellular concentration of acyl-CoAs revealed that the reductive reaction of butanoyl-CoA to butanal is a possible rate-limiting step. In addition, improvement of the butanoyl-CoA to butanal reaction resulted in an increased rate of acetyl-CoA synthesis by possibly compensating for the limitation of free CoA species. We inferred that the efficient recycling of free CoA played a key role in enhancing the conversion of pyruvate to acetyl-CoA.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s11306-015-0940-2) contains supplementary material, which is available to authorized users.</P>