CAJ | 학술논문

从以Mn代钼的固氮培养基中固氮生长的固氮菌(Azotobacter vinelandiiLipmann)突变种UW3中分离纯化的MnFe蛋白，在一定的结晶条件下，可从溶液中析出深棕色的短斜四棱柱晶体。Tris和Hepes缓冲液、NaCl、MgCl2和PEG的浓度及结晶方法等，对该蛋白的出晶率、晶核数目、晶体大小和质量均有明显的影响，PEG浓度的改变还可使该蛋白晶体的晶型发生变化。MnFe蛋白结晶所需的上述化合物的最适浓度与缺失nifZ固氮菌突变种ΔnifZ MoFe蛋白结晶所需的最适浓度有所不同。SDS凝胶电泳表明，晶体溶解后的蛋白与结晶前的MnFe蛋白基本相同。结果表明，该晶体为MnFe蛋白的晶体。
종이Mn대목적고담배양기중고담생장적고담균(Azotobacter vinelandiiLipmann)돌변충UW3중분리순화적MnFe단백，재일정적결정조건하，가종용액중석출심종색적단사사릉주정체。Tris화Hepes완충액、NaCl、MgCl2화PEG적농도급결정방법등，대해단백적출정솔、정핵수목、정체대소화질량균유명현적영향，PEG농도적개변환가사해단백정체적정형발생변화。MnFe단백결정소수적상술화합물적최괄농도여결실nifZ고담균돌변충ΔnifZ MoFe단백결정소수적최괄농도유소불동。SDS응효전영표명，정체용해후적단백여결정전적MnFe단백기본상동。결과표명，해정체위MnFe단백적정체。
Under a suitable condition of crystallization, dark brown shortrhombohedron crystals could be obtained from nitrogenase MnFe protein purified from a mutant UW3 of Azotobacter vinelandii Lipmann grown in Mn-containing but Mo- and NH3-free medium. The possibility of crystallization, and number,size and quality of crystals were obviously dependent on concentrations of NaCl,MgCl2, PEG 8000,Tris and Hepes buffer and on methods for crystallization. PEG concentration affected on the shape of the crystals.The optimal concentrations of the chemicals for crystallization of MnFe protein were slightly different from those for crystallization of ΔnifZ MoFe protein from a nifZ deleted strain of Azotobacter vinelandii. SDS-PAGE showed that the protein from the dissolved crystals was almost the same as MnFe protein before crystallization, indicating that the crystal was formed from MnFe protein.