Optimization of Determination of Intracellular S-Adenosyl-L-Methionine(SAM) Content and SAM Synthetase Activity by HPLC

The method for determination of S-adenosyl-L-methionine(SAM) content in cell extract of recombinant Pichia pastoris,as well as SAM synthetase activity of the enzymatic reaction mixture,by HPLC was studied.The composition of mobile phase and the gradient elution program were optimized to achieve a high resolution with a moderate retention time of SAM.As a result,a good linearity was observed for the calibration graph(R2=0.99996) in the range of 0.05 ~ 0.5 g·L-1 for SAM.The recoveries of SAM were 99.3%~100.5% and the relative standard deviation were 0.72%~0.98%.SAM in the cell extract sample or enzymatic reaction mixture could be separated effectively and determined accurately.