^ abcWilson JM, Fitschen PJ, Campbell B, Wilson GJ, Zanchi N, Taylor L, Wilborn C, Kalman DS, Stout JR, Hoffman JR, Ziegenfuss TN, Lopez HL, Kreider RB, Smith-Ryan AE, Antonio J (February 2013). "International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB)". Journal of the International Society of Sports Nutrition. 10 (1): 6. doi:10.1186/1550-2783-10-6. PMC3568064. PMID 23374455.
^Zanchi NE, Gerlinger-Romero F, Guimarães-Ferreira L, de Siqueira Filho MA, Felitti V, Lira FS, et al. (April 2011). "HMB supplementation: clinical and athletic performance-related effects and mechanisms of action". Amino Acids. 40 (4): 1015–1025. doi:10.1007/s00726-010-0678-0. PMID 20607321. S2CID 11120110. HMB is a metabolite of the amino acid leucine (Van Koverin and Nissen 1992), an essential amino acid. The first step in HMB metabolism is the reversible transamination of leucine to [α-KIC] that occurs mainly extrahepatically (Block and Buse 1990). Following this enzymatic reaction, [α-KIC] may follow one of two pathways. In the first, HMB is produced from [α-KIC] by the cytosolic enzyme KIC dioxygenase (Sabourin and Bieber 1983). The cytosolic dioxygenase has been characterized extensively and differs from the mitochondrial form in that the dioxygenase enzyme is a cytosolic enzyme, whereas the dehydrogenase enzyme is found exclusively in the mitochondrion (Sabourin and Bieber 1981, 1983). Importantly, this route of HMB formation is direct and completely dependent of liver KIC dioxygenase. Following this pathway, HMB in the cytosol is first converted to cytosolic β-hydroxy-β-methylglutaryl-CoA (HMG-CoA), which can then be directed for cholesterol synthesis (Rudney 1957) (Fig. 1). In fact, numerous biochemical studies have shown that HMB is a precursor of cholesterol (Zabin and Bloch 1951; Nissen et al. 2000).
^ abcKohlmeier M (May 2015). "Leucine". Nutrient Metabolism: Structures, Functions, and Genes (2nd ed.). Academic Press. pp. 385–388. ISBN978-0-12-387784-0. Retrieved 6 June 2016. Energy fuel: Eventually, most Leu is broken down, providing about 6.0kcal/g. About 60% of ingested Leu is oxidized within a few hours ... Ketogenesis: A significant proportion (40% of an ingested dose) is converted into acetyl-CoA and thereby contributes to the synthesis of ketones, steroids, fatty acids, and other compounds Figure 8.57: Metabolism of L-leucine
^Grünert SC, Stucki M, Morscher RJ, Suormala T, Bürer C, Burda P, et al. (May 2012). "3-methylcrotonyl-CoA carboxylase deficiency: clinical, biochemical, enzymatic and molecular studies in 88 individuals". Orphanet Journal of Rare Diseases. 7 (1): 31. doi:10.1186/1750-1172-7-31. PMC3495011. PMID 22642865.
^ abZanchi NE, Gerlinger-Romero F, Guimarães-Ferreira L, de Siqueira Filho MA, Felitti V, Lira FS, Seelaender M, Lancha AH (April 2011). "HMB supplementation: clinical and athletic performance-related effects and mechanisms of action". Amino Acids. 40 (4): 1015–1025. doi:10.1007/s00726-010-0678-0. PMID 20607321. S2CID 11120110. HMB is a metabolite of the amino acid leucine (Van Koverin and Nissen 1992), an essential amino acid. The first step in HMB metabolism is the reversible transamination of leucine to [α-KIC] that occurs mainly extrahepatically (Block and Buse 1990). Following this enzymatic reaction, [α-KIC] may follow one of two pathways. In the first, HMB is produced from [α-KIC] by the cytosolic enzyme KIC dioxygenase (Sabourin and Bieber 1983). The cytosolic dioxygenase has been characterized extensively and differs from the mitochondrial form in that the dioxygenase enzyme is a cytosolic enzyme, whereas the dehydrogenase enzyme is found exclusively in the mitochondrion (Sabourin and Bieber 1981, 1983). Importantly, this route of HMB formation is direct and completely dependent of liver KIC dioxygenase. Following this pathway, HMB in the cytosol is first converted to cytosolic β-hydroxy-β-methylglutaryl-CoA (HMG-CoA), which can then be directed for cholesterol synthesis (Rudney 1957) (Fig. 1). In fact, numerous biochemical studies have shown that HMB is a precursor of cholesterol (Zabin and Bloch 1951; Nissen et al. 2000).
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methylcrotonyl, confused, with, intermediate, metabolism, leucine, names, iupac, name, phosphonoadenosine, hydroxy, methyl, methylbut, enoyl, sulfanyl, ethyl, amino, oxopropyl, amino, oxobutyl, dihydrogen, diphosphate, preferred, iupac, name, amino, purin, hyd. Not to be confused with MG CoA 3 Methylcrotonyl CoA b Methylcrotonyl CoA or MC CoA is an intermediate in the metabolism of leucine 1 2 3 Methylcrotonyl CoA Names IUPAC name 3 O Phosphonoadenosine 5 3R 3 hydroxy 2 methyl 4 3 2 3 methylbut 2 enoyl sulfanyl ethyl amino 3 oxopropyl amino 4 oxobutyl dihydrogen diphosphate Preferred IUPAC name O1 2R 3S 4R 5R 5 6 Amino 9H purin 9 yl 4 hydroxy 3 phosphonooxy oxolan 2 yl methyl O3 3R 3 hydroxy 2 methyl 4 3 2 3 methylbut 2 enoyl sulfanyl ethyl amino 3 oxopropyl amino 4 oxobutyl dihydrogen diphosphate Identifiers CAS Number 6712 03 4 3D model JSmol Interactive image MeSH Methylcrotonyl CoA PubChem CID 439869 InChI InChI 1S C26H42N7O17P3S c1 14 2 9 17 35 54 8 7 28 16 34 5 6 29 24 38 21 37 26 3 4 11 47 53 44 45 50 52 42 43 46 10 15 20 49 51 39 40 41 19 36 25 48 15 33 13 32 18 22 27 30 12 31 23 18 33 h9 12 13 15 19 21 25 36 37H 5 8 10 11H2 1 4H3 H 28 34 H 29 38 H 42 43 H 44 45 H2 27 30 31 H2 39 40 41 t15 19 20 21 25 m1 s1Key BXIPALATIYNHJN TVCSPYKZSA N SMILES CC CC O SCCNC O CCNC O C C C C COP O O OP O O OC C H 1 C H C H C H O1 N2C NC3 C N CN C32 N O OP O O O O C Properties Chemical formula C26H42N7O17P3S Molar mass 849 636 g mol Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Y verify what is Y N Infobox references It is found in mitochondria where it is formed from isovaleryl coenzyme A by isovaleryl coenzyme A dehydrogenase It then reacts with CO2 to yield 3 Methylcrotonyl CoA carboxylase 4 Leucine metabolism editLeucine metabolism in humans nbsp L Leucine Branched chain aminoacid aminotransferase a Ketoglutarate Glutamate Glutamate Alanine Pyruvate Muscle a Ketoisocaproate a KIC Liver a Ketoisocaproate a KIC Branched chain a ketoaciddehydrogenase mitochondria KIC dioxygenase cytosol Isovaleryl CoA b Hydroxyb methylbutyrate HMB Excretedin urine 10 40 HMB CoA b Hydroxy b methylglutaryl CoA HMG CoA b Methylcrotonyl CoA MC CoA b Methylglutaconyl CoA MG CoA CO2 CO2 O2 CO2 H2O CO2 H2O liver HMG CoAlyase Enoyl CoA hydratase Isovaleryl CoAdehydrogenase MC CoAcarboxylase MG CoAhydratase HMG CoAreductase HMG CoA synthase b Hydroxybutyratedehydrogenase Mevalonatepathway Thiolase Unknownenzyme b Hydroxybutyrate Acetoacetyl CoA Acetyl CoA Acetoacetate Mevalonate Cholesterol nbsp Human metabolic pathway for HMB and isovaleryl CoA relative to L leucine 1 5 3 Of the two major pathways L leucine is mostly metabolized into isovaleryl CoA while only about 5 is metabolized into HMB 1 5 3 See also editMethylcrotonyl CoA carboxylaseReferences edit a b c Wilson JM Fitschen PJ Campbell B Wilson GJ Zanchi N Taylor L Wilborn C Kalman DS Stout JR Hoffman JR Ziegenfuss TN Lopez HL Kreider RB Smith Ryan AE Antonio J February 2013 International Society of Sports Nutrition Position Stand beta hydroxy beta methylbutyrate HMB Journal of the International Society of Sports Nutrition 10 1 6 doi 10 1186 1550 2783 10 6 PMC 3568064 PMID 23374455 Zanchi NE Gerlinger Romero F Guimaraes Ferreira L de Siqueira Filho MA Felitti V Lira FS et al April 2011 HMB supplementation clinical and athletic performance related effects and mechanisms of action Amino Acids 40 4 1015 1025 doi 10 1007 s00726 010 0678 0 PMID 20607321 S2CID 11120110 HMB is a metabolite of the amino acid leucine Van Koverin and Nissen 1992 an essential amino acid The first step in HMB metabolism is the reversible transamination of leucine to a KIC that occurs mainly extrahepatically Block and Buse 1990 Following this enzymatic reaction a KIC may follow one of two pathways In the first HMB is produced from a KIC by the cytosolic enzyme KIC dioxygenase Sabourin and Bieber 1983 The cytosolic dioxygenase has been characterized extensively and differs from the mitochondrial form in that the dioxygenase enzyme is a cytosolic enzyme whereas the dehydrogenase enzyme is found exclusively in the mitochondrion Sabourin and Bieber 1981 1983 Importantly this route of HMB formation is direct and completely dependent of liver KIC dioxygenase Following this pathway HMB in the cytosol is first converted to cytosolic b hydroxy b methylglutaryl CoA HMG CoA which can then be directed for cholesterol synthesis Rudney 1957 Fig 1 In fact numerous biochemical studies have shown that HMB is a precursor of cholesterol Zabin and Bloch 1951 Nissen et al 2000 a b c Kohlmeier M May 2015 Leucine Nutrient Metabolism Structures Functions and Genes 2nd ed Academic Press pp 385 388 ISBN 978 0 12 387784 0 Retrieved 6 June 2016 Energy fuel Eventually most Leu is broken down providing about 6 0kcal g About 60 of ingested Leu is oxidized within a few hours Ketogenesis A significant proportion 40 of an ingested dose is converted into acetyl CoA and thereby contributes to the synthesis of ketones steroids fatty acids and other compounds Figure 8 57 Metabolism of L leucine Grunert SC Stucki M Morscher RJ Suormala T Burer C Burda P et al May 2012 3 methylcrotonyl CoA carboxylase deficiency clinical biochemical enzymatic and molecular studies in 88 individuals Orphanet Journal of Rare Diseases 7 1 31 doi 10 1186 1750 1172 7 31 PMC 3495011 PMID 22642865 a b Zanchi NE Gerlinger Romero F Guimaraes Ferreira L de Siqueira Filho MA Felitti V Lira FS Seelaender M Lancha AH April 2011 HMB supplementation clinical and athletic performance related effects and mechanisms of action Amino Acids 40 4 1015 1025 doi 10 1007 s00726 010 0678 0 PMID 20607321 S2CID 11120110 HMB is a metabolite of the amino acid leucine Van Koverin and Nissen 1992 an essential amino acid The first step in HMB metabolism is the reversible transamination of leucine to a KIC that occurs mainly extrahepatically Block and Buse 1990 Following this enzymatic reaction a KIC may follow one of two pathways In the first HMB is produced from a KIC by the cytosolic enzyme KIC dioxygenase Sabourin and Bieber 1983 The cytosolic dioxygenase has been characterized extensively and differs from the mitochondrial form in that the dioxygenase enzyme is a cytosolic enzyme whereas the dehydrogenase enzyme is found exclusively in the mitochondrion Sabourin and Bieber 1981 1983 Importantly this route of HMB formation is direct and completely dependent of liver KIC dioxygenase Following this pathway HMB in the cytosol is first converted to cytosolic b hydroxy b methylglutaryl CoA HMG CoA which can then be directed for cholesterol synthesis Rudney 1957 Fig 1 In fact numerous biochemical studies have shown that HMB is a precursor of cholesterol Zabin and Bloch 1951 Nissen et al 2000 nbsp This biochemistry article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Methylcrotonyl CoA amp oldid 1188129905, wikipedia, wiki, book, books, library,
