植物碳酸酐酶对稳定碳同位素分馏作用的影响

碳酸酐酶（CA）能够可逆地催化CO2和HCO2^-之间的快速转化。长久以来人们忽视了生物体中CA对稳定碳同位素分馏的影响。本文以微藻碳酸酐酶胞外酶为例，说明细胞的区室化和偶联反应可引起CA可逆催化HCO2^-和CO2的转化的不平衡，进而造成稳定碳同位素分馏，并给出体外实验和C4植物实验结果作为依据。此外，本文还讨论了CA对碳同位素分馏的影响的理论和实践意义。

The Effect of Plant Carbonic Anhydrase on the Fractionation of Stable Carbon Isotope

It was known that carbonic anhydrase(CA) can catalyze the rapid reversible conversions between CO2 and bicarbonate,but little attention was made to effects of carbonic andydrase upon the stable carbon isotope fractionation.This paper studied microalgae extracelluar carbonic anhydrase as an example to reveal the stable carbon isotope fractionation resulted from the disequilibrium of reversible conversions between CO2 and bicarbonate in cell compartmentation and coupling reaction procedures.This proposed mechanism actually accounted for some literature experiments on in vitro and C4 plants.Finally,this paper discussed the theoretical and the practical significances of the stable carbon isotope fractionation affected by CA.