Whole cell c2d2 reduction by all four mutants comparing to wild type and ni / v mutant was also detected . the result showed that only single a - gln194 substitution did not perturb the stereospecificity of protonation of c2d2 . the above comparing results indicate that in mofe protein ( 1 ) a a - gln190 site and its association with homocitrate are important for the transfer of electron / proton to femoco , while a - his194 site and the homocitrate are independent in h2 evolution 对四个突变株细胞的c _ 2d _ 2还原特性及还原产物中反式-顺式- 1 ， 2 -二氘代乙炔的比例进行了测定并与野生型及nifv突变株相比较，结果表明只有- gln ~ ( 194 )替换不影响c _ 2d _ 2还原产物中反式-顺式- 1 ， 2 -二氘代乙炔的比例，即未改变固氮酶还原c _ 2h _ 2加氢的立体构型的专一性。
2.
By observing the effect of acidity on the uv difference spectra of ehpg or hbed , the spectral characteristics of apoovotransferrin binding to metals and anions at ph 7 . 4 show that the reaction of apoovotransferrin with metals is related to deprotonation of the phenolic group of tyrosine of the metal binding sites , while the binding of apoovotransferrin to anions is associated with the protonation of the phenolic group of tyrosine of the anion binding sites 摘要通过观察酸度对模拟转铁蛋白小分子ehpg和hbed紫外差光谱的影响，结合脱铁伴清蛋白与金属离子、阴离子结合的光谱特性，推断脱铁伴清蛋白与金属离子的结合导致金属离子结合位点处酪氨酸酚羟基的去质子化，而与阴离子的结合导致阴离子结合位点处酪氨酸酚羟基的质子化。
