The Carboxylation of Phosphoenolpyruvate and Pyruvate
نویسندگان
چکیده
منابع مشابه
The Carboxylation of Phosphoenolpyruvate and Pyruvate I. THE ACTIVE SPECIES OF “COz” UTILIZED BY PHOSPHOENOLPYRUVATE
Previous studies with propionyl coenzyme A carboxylase and with phosphoenolpyruvate carboxylase using ‘*O-labeled bicarbonate have indicated that bicarbonate is the reactive species in these fixations of “C02.” We have investigated the species of CO:! in reactions catalyzed by pyruvate carboxylase, P-enolpyruvate carboxykinase, and P-enolpyruvate carboxytransphosphorylase. Since propionyl-CoA c...
متن کاملThe carboxylation of phosphoenolpyruvate and pyruvate. II. The active species of "CO2" utilized by phosphoenlpyruvate carboxylase and pyruvate carboxylase.
The active species of “COP,” i.e. CO2 or HCO,, utilized in the pyruvate carboxylase and phosphoenolypruvate carboxylase reaction have been determined with an assay predicated upon the fact that the hydration of CO2 is a kinetically slow and measurable reaction. The results of these assays in both cases are in reasonable agreement with those expected if HCOIis assumed to be the functional specie...
متن کاملStereochemistry of the enzymatic carboxylation of phosphoenolpyruvate.
Using specifically labeled 3-*H-phosphoenolpyruvate, the stereochemistry of CO2 (or HCOs) addition was determined for the reactions catalyzed by P-enolpyruvate carboxylase (from peanuts and Acetobocfer xytinum), P-enolpyruvate carboxykinase (from pigeon liver), and P-enolpyruvate carboxytransphosphorylase (from Propionibacterium shermanii). In all cases the addition occurs from the same side of...
متن کاملPhosphoenolpyruvate carboxylation and aspartate synthesis in Acetobacter suboxydans.
Dialyzed extracts of Acetobacter suboxydans ATCC 621 catalyze (14)CO(2) assimilation in the presence of phosphoenolpyruvate and a divalent cation. The formation of (14)C-oxalacetate was demonstrated and found not to be dependent upon the presence of orthophosphate or diphosphonucleotides. Oxalacetate synthesis was stimulated by orthophosphate and inhibited by aspartate. All attempts to demonstr...
متن کاملThe Enzymatic Carboxylation of Phosphoenolpyruvate III. INVESTIGATION OF THE KINETICS AND MECHANISM OF THE MITOCHONDRIAL PHOSPHO-
Comparative kinetic studies at pH 6.8, 7.3, and 8.0 reveal that the phosphoenolpyruvate carboxykinase-catalyzed inosine trlphosphate-dependent oxalacetate-H14C0sexchange is much more rapid than either the over-all decarboxylation or carboxylation reactions. At pH 6.8, the relative carboxylation, decarboxylation, and oxalacetate-H14C03exchange rates are 1.0, 8.3, and 30, respectively. While the ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1971
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)61931-3