Essential carboxyl groups in yeast hexokinase
نویسندگان
چکیده
منابع مشابه
Activators of yeast hexokinase.
The rate of the ATP:glucose transphosphorylase reaction catalyzed by yeast hexokinase, isozyme PII, is inhibited by lowering the pH of the reaction below 7.0, especially at suboptimal concentrations of ATP. This effect of acidity is largely overcome by activators such as orthophosphate, citrate, malate, 3-phosphoglycerate, and riboside triphosphates. Thus, in the acid range, ATP appears to serv...
متن کاملActivation of Yeast Hexokinase PI1
Activation of yeast hexokinase PI1 at low pH by citrate or ATP has been shown to occur at the monomer level, without requiring association to the dimer level. Thus, the previous suggestion (Steitz, T. A., Anderson, W. F., Fletterick, R. G., and Anderson, C. M. (1977) J. Biol. Chem. 252, 4494-4500) that anionic activators of hexokinase, such as citrate and ATP, act by binding to the intersubunit...
متن کاملKinetic studies of yeast hexokinase.
The mechanism of calf brain hexokinase has recently been studied in our laboratory (1). It was concluded from kinetic experiments that adenosine diphosphate (ADP) dissociates from the enzyme before addition of substrate glucose. This hypothesis was supported by kinetic studies of n-mannose, ADP, and glucose g-phosphate inhibition. The experiments appear to lend credence to theories in which an ...
متن کاملGlucose-induced conformational change in yeast hexokinase.
The A isozyme of yeast hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) crystallized as a complex with glucose has a conformation that is dramatically different from the conformation of the B isozyme crystallized in the absence of glucose. Comparison of the high-resolution structures shows that one lobe of the molecule is rotated by 12 degrees relative to the other lobe, resulting in ...
متن کاملCarboxyl groups near the active site zinc contribute to catalysis in yeast alcohol dehydrogenase.
The importance of carboxyl groups near the active site zinc for the catalytic function of alcohol dehydrogenase I from Saccharomyces cerevisiae was examined by directed mutagenesis and steady state kinetics. Asp-49 was changed to asparagine and Glu-68 to glutamine (residue numbering as for horse liver enzyme). The catalytic efficiencies (V/Km) for ethanol oxidation and acetaldehyde reduction we...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: FEBS Letters
سال: 1974
ISSN: 0014-5793
DOI: 10.1016/0014-5793(74)80824-0