SYNTHESIS OF 13C & 2H LABELED GLYCEROL & DIHYDROXY ACETONE

SIR提供K-77SECN(硒氰酸钾)；117毫克A 在氢酶中发现的双核活性中心的模型已经被 准备好了并进行了表征。该模型由两个镍中心组成 由两个硫酸盐配体桥联，并具有一个末端的硫酸盐和 一个叔胺连接到每个镍中心(Choudhury等人)。Inorg. 化学。1994、33、4831-4839)。为了考察其作用， 硒半胱氨酸取代了一些酶，我们已经取代了 模型中硫代硫酸盐中的硒酸盐(同上)。我们希望应用核磁共振技术 和Endor光谱学到这些模型中，以期 酶也是一样的。这些技术将使我们能够直接探测 镍硒半胱氨酸配体在酶催化中的作用。这个 拟议的模型研究将使我们能够开发Endor技术 并提供用于解释酶数据的数据库。 这些研究需要用77Se来富集硒核， 具有核磁矩(i=1/2)的Se的同位素。我们会 按已公布的程序合成模型化合物 K(77SeCN)由LANL的稳定同位素资源产生。vt.在.的基础上 成功完成模型研究后，酶样本将 通过添加所涉及的细菌的生长介质制备的 (如脱硫菌、巴氏杆菌或伏特氏甲烷球菌) 77Se.

The SIR provided K 77 SeCN (Potassium Selenocyanate); 117mg A model of the dinuclear active site found in hydrogenases has been prepared and characterized. This model consists of two Ni centers bridged by two thiolate ligands and having one terminal thiolate and one tertiary amine liganded to each Ni center (Choudhury et al. Inorg. Chem. 1994, 33, 4831-4839). In order to examine the role of selenocysteine substitution in some enzymes, we have substituted selenolates for thiolates in the model (ibid.). We wish to apply NMR and ENDOR spectroscopy to these models in anticipation of doing the same for the enzyme. These techniques will allow us to directly probe the role of the Ni selenocysteine ligand in enzyme catalysis. The proposed model studies will allow us to develop the ENDOR technique and to provide a data base with which to interpret the enzyme data. These studies require enrichment of the selenium nucleus by 77Se, the isotope of Se with a nuclear magnetic moment (I = 1/2). We will synthesize the model compound by the published procedure employing K(77SeCN) produced by the Stable Isotope Resource at LANL. Upon successful completion of the model studies, enzyme samples will be prepared by supplementing the growth medium of the bacteria involved (e.g., Desulfomicrobiurn baculaturn or Methanococcus voltae) with 77Se.