241 human active and 13 inactive phosphatases in total;
194 phosphatases have substrate data;
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336 protein substrates;
83 non-protein substrates;
1215 dephosphorylation interactions;
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299 KEGG pathways;
876 Reactome pathways;
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last scientific update: 11 Mar, 2019
last maintenance update: 01 Sep, 2023
The branched-chain alpha-keto dehydrogenase complexcatalyzes the overall conversion of alpha-keto acids to acyl-CoAand CO(2) It contains multiple copies of three enzymaticcomponents: branched-chain alpha-keto acid decarboxylase (E1),lipoamide acyltransferase (E2) and lipoamide dehydrogenase (E3)
Glyoxylate is generated in the course of glycine and hydroxyproline catabolism and can be converted to oxalate. In humans, this process takes place in the liver. Defects in two enzymes of glyoxylate metabolism, alanine:glyoxylate aminotransferase (AGXT) and glycerate dehydrogenase/glyoxylate reductase (GRHPR), are associated with pathogenic overproduction of oxalate (Danpure 2005). The reactions that interconvert glycine, glycolate, and glyoxylate and convert glyoxylate to oxalate have been characterized in molecular detail in humans. A reaction sequence for the conversion of hydroxyproline to glyoxylate has been inferred from studies of partially purified extracts of rat and bovine liver but the enzymes involved in the corresponding human reactions have not been identified
The branched-chain amino acids, leucine, isoleucine, and valine, are all essential amino acids (i.e., ones required in the diet). They are major constituents of muscle protein. The breakdown of these amino acids starts with two common steps catalyzed by enzymes that act on all three amino acids: reversible transamination by branched-chain amino acid aminotransferase, and irreversible oxidative decarboxylation by the branched-chain ketoacid dehydrogenase complex. Isovaleryl-CoA is produced from leucine by these two reactions, alpha-methylbutyryl-CoA from isoleucine, and isobutyryl-CoA from valine. These acyl-CoA's undergo dehydrogenation, catalyzed by three different but related enzymes, and the breakdown pathways then diverge. Leucine is ultimately converted to acetyl-CoA and acetoacetate; isoleucine to acetyl-CoA and succinyl-CoA; and valine to succinyl-CoA. Under fasting conditions, substantial amounts of all three amino acids are generated by protein breakdown. In muscle, the final products of leucine, isoleucine, and valine catabolism can be fully oxidized via the citric acid cycle; in liver they can be directed toward the synthesis of ketone bodies (acetoacetate and acetyl-CoA) and glucose (succinyl-CoA) (Chuang & Shih 2001, Sweetman & Williams 2001)
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