Pope M R, Murrell S A, Ludden P W
Biochemistry. 1985 Apr 23;24(9):2374-80. doi: 10.1021/bi00330a037.
Nitrogenase in Rhodospirillum rubrum is regulated in vivo by the covalent modification of the Fe protein. This paper reports the isolation, purification, and properties of the modifying group that has been heat released from the Fe protein. The molecule is isolated from the heated mixture by binding to a boronate affinity column. Purification is achieved on an ion-exchange high-performance liquid chromatography column. Structural properties of the molecule have been investigated by using proton and phosphorus NMR, mass spectrometry, enzyme susceptibility, and chromatographic methods. The heat-released modifying group exhibits an unusual signal in the proton NMR spectrum at 1.26 ppm. The molecule also contains a functional group which can be reduced by borohydride. This group is lost on breakdown of the molecule or upon treatment of the molecule with 5'-nucleotidase. The identity of the base and the pentose of modifying group as adenine and ribose, respectively, is confirmed. Ratios of the known components of the modifying group are established.
深红红螺菌中的固氮酶在体内通过铁蛋白的共价修饰进行调控。本文报道了从铁蛋白中热释放出来的修饰基团的分离、纯化及性质。该分子通过与硼酸酯亲和柱结合从加热混合物中分离出来。在离子交换高效液相色谱柱上实现纯化。通过质子和磷核磁共振、质谱、酶敏感性及色谱方法研究了该分子的结构性质。热释放的修饰基团在质子核磁共振谱中于1.26 ppm处呈现出异常信号。该分子还含有一个可被硼氢化物还原的官能团。该基团在分子分解或用5'-核苷酸酶处理分子时会丢失。分别确认了修饰基团的碱基和戊糖为腺嘌呤和核糖。确定了修饰基团已知成分的比例。
