Yeast adenylate kinase

Treatment of 9-(/ -D-ribofuranosyluronic acid)adenine with diphenylphosphoro-chloridate and orthophosphate or tripolyphosphate yields (62) and (63), which, although unstable, inhibit rabbit AMP aminohydrolase and pyruvate kinase, respectively, with behaviour characteristic of active-site-specific reagents.98 Adenylate kinases from several sources are inactivated by iV6-[2- and 4-fluorobenzoyl]-adenosine-5 -triphosphates, with kinetics characteristic of active-site labelling, although these compounds were without effect on yeast hexokinase and rabbit pyruvate kinase.99... 

The enzyme was purified from yeast and was free of N MN adenyltrans-ferase, ATPase, and adenylate kinase activities. 

Khoo JC, Russsel PJ Jr. Adenylate kinase from bakers yeast. IV. Substrate and inhibitor structural requirements. J. Biol. Chem. 1970 245 4163-4167. 

Adenylate kinase (myokinase) inhibitors 0.06% Hexokinase (yeast)... 

The AP2-PL was initially shown to inactivate lactate dehydrogenase (88), hexokinase, adenylate kinase, and 3-phosphoglycerate kinase (89). Yeast hexo-kinase binds AP2-PL, with a Ka value of 23 /xM (90), prior to inactivation. 

Of primary importance are enzymes which catalyse phosphate transfer or phosphorylation. These have been known variously as kinases, phosphotransferases phosphorylases, phosphokinases, trans-phosphorylases and so on. They show a wide range of molecular weights. Adenylate kinase, for example, has a molecular weight of 21,000, whereas yeast fructokinase has a molecular weight of 580,000. 

Thiamine is metabolized to TPP by thiamine pyrophosphokinase (EC 2.1.62) in animal cells including red and white blood cells. This enzyme is also present in plants, yeast, and a bacterium (Paracoccus denitrificans) (7). However, in some bacteria, for example in Escherichia coli, thiamine is metabolized to TPP by a two-step reaction catalyzed by thiamine kinase (EC 2.7.1.89) and TMP kinase (EC 2.7.4.10). Thiamine pyrophosphate is further metabolized to TI P in yeast, animal tissues, and human red blood cells. Evidence has been obtained which indicates that cytosolic adenylate kinase (EC 2.7.4.3) catalyzes TIP synthesis from TPP in vitro (8) and in vivo (3). The enzyme system involved in thiamine metabolism to TTP in human red blood cells was recently identified, purified, and reconstituted (9). 

The adenylate kinases from the three bacteria studied were found to be heat-labile. Enzymes revealing similar behavior were described for rat liver (Sapico et al., 1972), baker s yeast (Chiu et al., 1967), Escherichia coli (Holmes and Singer, 1973), Pseudomonas denitrificans (Terai, 1974) and from spinach chloroplast evelopes (Murakami and Strotmann, 1978). On the other hand, the adenylate kinase from muscle or beef heart mitochondria were reported to be heat-stable (Albrecht, 1970 Colowick and Kalckar, 1943). 

Chiu C, Su S and Russel PJ (1967) Adenylate kinase from baker s yeast. 

Adenylate cyclase was identified as the primary Ras target in yeast (Saccha-romyces cerevisiae) [56] but it took a while before in 1993 several groups independently found Raf to be the effector of Ras in mammals [41-44]. Shortly afterwards it was realized that this is not the only target of Ras but up until now it appears to be the most prominent one. Raf is a Ser/Thr-specific protein kinase which phosphorylates and thereby activates Mek which in turn phosphorylates and activates Erk, leading to an amplification of the signal. Erk, also termed MAPK, has a plethora of phosphorylation targets, the most important of which are transcription factors such as Elk-1, leading to activation of the transcription machinery in the nucleus. 

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