STUDIES ON ADENOSINE TRIPHOSPHATE TRANSPHOSPHORYLASES

(1)从兔的头部和尾部提取的两个肽段， 肌肉肌激酶具有显着且特异性的配体结合作用 特性. 通过系统的合成和平衡测定， 这两组肽的底物结合包括结合 家兔的MgATP 2-和MgADP-位点（a）和ADP 3-和AMP 2-位点（B 肌肉肌激酶，它是希望化学概述和推导出 底物与ATP-AMP转磷酸酶结合的要求。 一种合成肽（11-45，兔肌激酶的残基1-45）， 目前正在研究通过核磁共振技术，以进一步描绘其配体 交互. 作为最后阶段，将试图综合 酶活性片段。 (2)提供关于基本过程的信息， ATP转磷酸化，一种比较物理化学的方法， 继续讨论几种酶，这些酶具有催化 ATP的磷酰基或焦磷酰基转移到 合适受体，但其底物特异性显著不同 对接受者的要求。 这些研究包括以下系列 酶：兔和小牛的腺苷酸激酶同工酶;核苷 来自酵母的二磷酸激酶;来自兔的肌酸激酶同工酶， 小牛;猪脑硫胺素焦磷酸激酶。 总氨基酸 兔和小牛肌肉腺苷酸激酶的序列和兔 肌肌酸激酶最近有报道。 努力目前 进行中（a）制备适用于X光的肌酸激酶晶体 分析，以及（B）制备88个残基的片段，其可以 包括肌酸激酶的ATP结合位点。 (3)随着令人兴奋的发现，一种异常的腺苷酸激酶， Duchenne营养不良血清，我们的目标相应地扩展到 包括对腺苷酸激酶的人同工酶的详细研究（和 肌酸激酶）。 人们希望 这些研究可能有助于了解Duchenne营养不良的遗传学。 最近从杜氏酵母中分离出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的 结构以及正常人肝型腺苷酸激酶的结构， 与之相似

(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.