scholarly journals Synthesis of 3-arsonopyruvate and its interaction with phosphoenolpyruvate mutase

1995 ◽  
Vol 308 (3) ◽  
pp. 931-935 ◽  
Author(s):  
S Chawla ◽  
E K Mutenda ◽  
H B F Dixon ◽  
S Freeman ◽  
A W Smith
Keyword(s):  
Lactate Dehydrogenase ◽  
Propionic Acid ◽  
Natural Substrate ◽  
Alternative Substrate ◽  
Carbon Bond ◽  
Phosphoenolpyruvate Mutase

3-Arsonopyruvate was prepared in four steps from glycine. The arsenic-carbon bond was formed by a Meyer reaction between alkaline arsenite and 2-bromo-3-hydroxy-2-(hydroxymethyl)propionic acid; the 3-arsono-2-hydroxy-2-(hydroxymethyl) propionic acid formed was oxidized with periodate to give 3-arsonopyruvate. This proves to be an alternative substrate for phosphoenolpyruvate mutase, giving pyruvate, which was assayed using lactate dehydrogenase. The K(m) is 20 microM, similar to that observed for the natural substrate phosphonopyruvate (17 microM), whereas the kcat. of 0.01 s-1 was much lower than that for phosphonopyruvate (58 s-1). Arsonopyruvate competitively inhibited the action of the mutase on phosphonopyruvate.

Rates of disappearance from plasma of enzymes labeled by coupling with a radioactive lodo-ester.

1976 ◽  
Vol 22 (8) ◽  
pp. 1277-1282
Author(s):  
A R Qureshi ◽  
J H Wilkinson
Keyword(s):  
Creatine Kinase ◽  
Catalytic Activity ◽  
Lactate Dehydrogenase ◽  
Propionic Acid ◽  
Free Acid ◽  
Rabbit Muscle ◽  
Analytical Recovery ◽  
Catalytically Active ◽  
Rapid Hydrolysis

Abstract Lactate dehydrogenase-5 and creatine kinase from rabbit muscle were labeled by coupling with N-hydroxysuccinimidyl 3-(4'-hydroxy-[3',5'-125I]diiodophenyl)propionate. After purification, the analytical recovery of catalytically-active labeled enzyme averaged 90% for lactate dehydrogenase, 81% for creatine kinase. The labeled enzymes were injected intravenously into rabbits and disappearance from plasma of catalytic activity and radioactivity was measured. The disappearance curves for lactate dehydrogenase-5 differed considerably from those observed with the enzyme labeled by direct iodination. The discrepancy was due to rapid hydrolysis in vivo of the labeled amide-enzyme linkage, because about 50% of the injected radioactivity appeared in the urine as 125I-labeled 3-(4'-hydroxy-3',5'-diiodophenyl)propionic acid within 4-8 h of injection. Similar outputs were observed after administration of this acid to rabbits. The free acid was also detected in the urines of rabbits within 4-8 h of the intravenous injection of creatine kinase labeled similarly. We conclude that this method of labeling is unsuitable for preparing radioactive enzymes for study of their catabolism.

scholarly journals Kinetic co-operativity of wheat-germ RNA polymerase II with adenosine 5′-[βγ-imido]triphosphate as substrate

1988 ◽  
Vol 252 (1) ◽  
pp. 55-63 ◽  
Author(s):  
C Job ◽  
J M Soulié ◽  
D Job
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Kinetic Models ◽  
Metal Ion ◽  
Wheat Germ ◽  
Substrate Recognition ◽  
Chain Elongation ◽  
Velocity Versus ◽  
Natural Substrate ◽  
Alternative Substrate

A kinetic study of productive RNA chain elongation indicates that adenosine 5′-[beta gamma-imido]triphosphate can serve as substrate in reactions catalysed by purified wheat-germ RNA polymerase II on a poly[d(A-T)] template. However, in contrast with the results obtained with the natural substrate ATP, the double-reciprocal plots, 1/velocity versus 1/[nucleotide], are not linear but characteristic of apparent negative co-operativity. The extent of the kinetic co-operativity is modified when the reactions are conducted in the additional presence of fixed amounts of an alternative substrate such as ATP or inhibitors such as dATP or cordycepin triphosphate. Analogous results are obtained whether the reactions are carried out in the presence of Mg2+ or Mn2+ as the metal ion cofactor. However, the data show that with Mn2+ the RNA polymerase is less specific in substrate recognition than with Mg2+. Tentative kinetic models are proposed to account for the rate measurements.

Serum Lactate Dehydrogenase Isoenzyme 1 and Relapse in Patients with Nonseminomatous Testicular Germ Cell Tumors Clinical Stage I

2001 ◽  
Vol 40 (4) ◽  
pp. 536-540 ◽  
Author(s):  
Finn Edler von Eyben ◽  
Ebbe Lindegaard Madsen ◽  
Ole Blaabjerg ◽  
Per Hyltoft Petersen ◽  
Hans von der Maase ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Germ Cell ◽  
Clinical Stage ◽  
Germ Cell Tumors ◽  
Serum Lactate ◽  
Stage I ◽  
Serum Lactate Dehydrogenase ◽  
Testicular Germ Cell Tumors ◽  
Testicular Germ Cell ◽  
Dehydrogenase Isoenzyme

Lactate Dehydrogenase-Linked Immunoglobulin A K in a Patient with Nonimmune Chronic Idiopathic Neutropenia

2006 ◽  
Vol 12 (3) ◽  
pp. 148-151
Author(s):  
Noriko Ihara ◽  
Ikuo Murohashi ◽  
Masako Itho ◽  
Ikuo Amino ◽  
Katsuhiko Yoshida ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Immunoglobulin A ◽  
Chronic Idiopathic Neutropenia
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