Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.2.1.1 (ACS)
 78,556 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Homogenates of rat epididymal fat pad, heart, kidney, lactating mammary gland, liver, skeletal muscle and small intestinal mucosa have been partitioned into a particulate and supernatant fraction. With reliable marker enzymes for the mitochondrial matrix and the cytosol: propionyl-CoA carboxylase and pyruvate kinase, the distributions of the acyl-CoA synthetase activities measured at 1 and 10 mM C2, C3 and C4 over mitochondria and cytosol have been calculated. From these values an estimate was made of the K0.5 of the fatty acids. 2. A distinct fatty acid-activating enzyme was assumed to be present in one of the compartments when that fatty acid was activated with a K0.5 less than or equal to 1.5 mM in an amount of greater than 13% of the total cellular activity. Adipose tissue, gut, liver and mammary gland, all organs of a high lipogenetic capacity, contained a cytosolic acetyl-CoA synthetase. At 1 mM acetate 60, 31, 77 and 83% of the total cellular activities in these organs were cytosolic in nature, with activities of 0.021, 0.32, 0.37 and 1.16 mumol C2 activated per min per g wet weight, respectively. 3. Mitochondrial acetyl-CoA and butyryl-CoA synthetases were found in adipose tissue, gut, heart, kidney, mammary gland and muscle. They were absent in liver. Adipose tissue and liver contained a mitochondrial propionyl-CoA synthetase with activities at 1 mM C3 of 0.014 and 1.50 mumol C3 activated per min per g wet weight, respectively. 4. At 1 mM, C2 was activated with decreasing rates by kidney, heart, mammary gland and gut (7.6-1.0 mumol C2 activated per min per g wet weight). C3 (1 mM) activation was about equal (1.6-1.9 mumol C3 activated per min per g wet weight) in liver, kidney and heart. C4 (1 mM) was activated with decreasing rates by heart, liver, kidney and gut (4.0-0.5 mumol C4 activated per min per g wet weight) in the order given. 5. The influence of the isolation method and the diet on fatty acid activation in small intestinal mucosal scrapings have been studied. To demonstrate the existence of cytosolic acetyl-CoA synthetase in fed animals a pre-treatment of everted intestine by low amplitude vibration has been found essential. Also C16 activation was highly (95%) decreased in a non-pre-vibrated preparation. 24 h starvation lowered cytosolic C2 and total C16 activation by 90 and 80%, respectively. Refeeding of starved rats with a balanced fat-free diet, and not with sucrose only, gave the same cytosolic C2 and total C16 activation as normally fed rats. 6. In guienea-pig heart, kidney, liver and muscle about the same partitions have been found as in the respective rat organs. The acetate activation in liver was factor 6 lower. Acetate and butyrate activation in guinea-pig muscle was much higher (6 and 37 times, respectively).
 ...
PMID:Organ and intracellular localization of short-chain acyl-CoA synthetases in rat and guinea-pig. 120 46

On the basis of enzyme activities detected in extracts of Selenomonas ruminantium HD4 grown in glucose-limited continuous culture, at a slow (0.11 h-1) and a fast (0.52 h-1) dilution rate, a pathway of glucose catabolism to lactate, acetate, succinate, and propionate was constructed. Glucose was catabolized to phosphoenol pyruvate (PEP) via the Emden-Meyerhoff-Parnas pathway. PEP was converted to either pyruvate (via pyruvate kinase) or oxalacetate (via PEP carboxykinase). Pyruvate was reduced to L-lactate via a NAD-dependent lactate dehydrogenase or oxidatively decarboxylated to acetyl coenzyme A (acetyl-CoA) and CO2 by pyruvate:ferredoxin oxidoreductase. Acetyl-CoA was apparently converted in a single enzymatic step to acetate and CoA, with concomitant formation of 1 molecule of ATP; since acetyl-phosphate was not an intermediate, the enzyme catalyzing this reaction was identified as acetate thiokinase. Oxalacetate was converted to succinate via the activities of malate dehydrogenase, fumarase and a membrane-bound fumarate reductase. Succinate was then excreted or decarboxylated to propionate via a membrane-bound methylmalonyl-CoA decarboxylase. Pyruvate kinase was inhibited by Pi and activated by fructose 1,6-bisphosphate. PEP carboxykinase activity was found to be 0.054 mumol min-1 mg of protein-1 at a dilution rate of 0.11 h-1 but could not be detected in extracts of cells grown at a dilution rate of 0.52 h-1. Several potential sites for energy conservation exist in S. ruminantium HD4, including pyruvate kinase, acetate thiokinase, PEP carboxykinase, fumarate reductase, and methylmalonyl-CoA decarboxylase. Possession of these five sites for energy conservation may explain the high yields reported here (56 to 78 mg of cells [dry weight] mol of glucose-1) for S. ruminantium HD4 grown in glucose-limited continuous culture.
 ...
PMID:Pathway and sites for energy conservation in the metabolism of glucose by Selenomonas ruminantium. 314 85