N_2键合在固氮酶M簇笼内的一个可能证据

A Proof for N_2-binding Inside M-cluster Cage of Nitrogenase

研究了重水固氮酶体系中Ｎ_２对Ｃ_２Ｈ_２的还原活性和立体化学产物的影响，发现Ｎ_２的存在不仅抑制了Ｃ_２Ｈ_２的还原活性，而且提高了产物乙烯中反式１．２－二氘代乙烯的相对含量，为证实Ｎ_２在固氮酶Ｍ簇合物笼内的还原氢化提供了一个有力的证据。

The experiments that the reductive deuteration and products-selectivity of C_2H_2 are affected by N_2 in D_2O-nitgrogenase have been done. It is found that the C_2H_2 reductive activities decreased ca. 80.7%and 89.3%,respectively,with mixtures of C_2H_2and N_2 in the ratios of 1:108.3 and 1:216.7(volume ratio),as compared with ca. 42.6%and 74.2% observed with C_2H_2 in argon(1:65 and 1:108.3,volume ratio) in the absence of N_2;ca. 3.19%and 4.95%trans-2-didutero ethene were observed form FTIR spectra of the ethenes-1,2-d_2 obtained, respectively,with mixtures of C_2H_2 and N_2 in the ratios of1:108.3 and 1:216.7(volume ratio).The results give a strong proof for the conclusion in which N_2 binds inside the cage of M-cluster.