STUDIES ON ADENOSINE TRIPHOSPHATE TRANSPHOSPHORYLASES

(1)兔的前部和尾部的两个多肽片段 肌肉肌酸激酶具有显著和特异的配体结合 属性。通过系统地合成和测量它们的平衡 包含结合的这两组肽的底物结合 兔的MgATP2-和MgADP-和ADP3-和Amp2-的结合位点 肌肉肌酸激酶，希望能从化学上勾勒和推导出 底物与ATP-AMP转磷酸酶结合的要求。 一种合成肽(11-45，兔肌激酶残基1-45)是 目前正在进行核磁共振技术研究，以进一步确定其配体 互动。作为结束阶段，我们将尝试合成 酶活性片段(S)。 (2)提供有关基本程序的资料 ATP转磷酸化，一种比较的物理化学方法正在进行 继续使用几种具有共同催化能力的酶 将三磷酸腺苷的磷酰基或焦磷酰基转移到 合适的受体，但底物专一性明显不同 对接受者的要求。这些研究包括以下系列 酶类：兔和小牛的腺苷酸激酶同工酶；核苷 来自酵母的二磷酸肌酸激酶；来自兔的肌酸激酶同工酶和来自 小牛；猪脑中的硫胺素焦磷酸激酶。总氨基酸 兔和小腿肌腺苷酸激酶及兔的序列 肌肉肌酸激酶最近有报道。现在正在努力 正在进行(A)制备适用于X射线的肌酸激酶晶体 分析，以及(B)制备88个残基的片段，其可以 包含肌酸激酶的ATP结合部位。 (3)令人兴奋地发现了一种来自 Duchenne营养不良血清，我们的目标相应扩大到 包括对人类腺苷酸激酶同工酶的详细研究(和 肌酸激酶)来自正常和异常组织。人们希望， 这些研究可能有助于揭示Duchenne营养不良的遗传学。 最近，从杜氏藻中分离到了异常的腺苷酸激酶 营养不良血清，目前正在努力推断其主要 结构以及正常的人类肝型腺苷酸激酶的结构， 它与之有相似之处。

(1) The two peptide fragments derived from the front and the tail of rabbit muscle myokinase possess remarkable and specific ligand-binding properties. By systematic syntheses and measurements of their equilibrium substrate binding of these two sets of peptides which encompass the binding sites (a) for MgATP2- and MgADP- and (b) for ADP3- and AMP2- of rabbit muscle myokinase, it is hoped to chemically outline and deduce the requirements for binding of the substrates to ATP-AMP transphosphorylase. One synthetic peptide (11-45, residues 1-45 of rabbit muscle myokinase) is currently under study by NMR techniques to further delineate its ligand interactions. As a concluding phase, attempts will be made to synthesize enzymatically active fragment(s). (2) To provide information on the basic process of ATP-transphosphorylation, a comparative physicochemical approach is being continued on several enzymes which have in common the ability to catalyze the transfer of a phosphoryl group, or pyrophosphoryl group, of ATP to a suitable acceptor, but which differ markedly in their substrate specificity requirements for the acceptor. These studies include the following series of enzymes: adenylate kinase isoenzymes from rabbit and calf; nucleoside diphosphokinase from yeast; creatine kinase isoenzymes from rabbit and calf; thiamin pyrophosphokinase from porcine brain. The total amino acid sequence of the rabbit and calf muscle adenylate kinases and of rabbit muscle creatine kinase have recently been reported. Efforts are now underway (a) to prepare crystals of creatine kinase suitable for X-ray analysis, and also (b) to prepare a fragment of 88 residues which may encompass the ATP-binding site of creatine kinase. (3) With the exciting discovery of an aberrant adenylate kinase from Duchenne dystrophic serum, our objectives were accordingly extended to include a detailed study of the human isoenzymes of adenylate kinase (and of creatine kinase) from normal and abnormal tissues. It is hoped that these studies may shed light on the genetics of Duchenne dystrophy. Recently the aberrant adenylate kinase has been isolated from Duchenne dystrophic serum, and efforts are now underway to deduce its primary structure as well as that of the normal human liver-type adenylate kinase, to which it bears a resemblance.