Ensiklopedia Dunia

MHG-KoA
Nama
	Nama IUPAC asam(9R,21S)-1-[(2R,3S,4R,5R)-5-(6-amino-9H-purin-9-il)-4-hidroksi-3-(fosfonooksi)tetrahidrofuran-2-il]-3,5,9,21-tetrahidroksi-8,8,21-trimetil-10,14,19-triokso-2,4,6-trioksa-18-tia-11,15-diaza-3,5-difosfatrikosan-23-oat 3,5-dioksida
	Nama lain 3-hidroksi-3-metilglutaril KoA; 3-hidroksi-3-metilglutaril koenzim A
Penanda
Nomor CAS	1553-55-5 ;
Model 3D (JSmol)	Gambar interaktif;
ChEBI	CHEBI:61659 ;
ChemSpider	392859 ;
Nomor EC
IUPHAR/BPS	3040;
MeSH	HMG-CoA
PubChem CID	445127;
Nomor RTECS	{{{value}}}
CompTox Dashboard (EPA)	DTXSID40862689 DTXSID00935181, DTXSID40862689 ;
	InChI InChI=1S/C27H44N7O20P3S/c1-26(2,21(40)24(41)30-5-4-15(35)29-6-7-58-17(38)9-27(3,42)8-16(36)37)11-51-57(48,49)54-56(46,47)50-10-14-20(53-55(43,44)45)19(39)25(52-14)34-13-33-18-22(28)31-12-32-23(18)34/h12-14,19-21,25,39-40,42H,4-11H2,1-3H3,(H,29,35)(H,30,41)(H,36,37)(H,46,47)(H,48,49)(H2,28,31,32)(H2,43,44,45)/t14-,19-,20-,21+,25-,27+/m1/s1 Key: CABVTRNMFUVUDM-VRHQGPGLSA-N ; InChI=1/C27H44N7O20P3S/c1-26(2,21(40)24(41)30-5-4-15(35)29-6-7-58-17(38)9-27(3,42)8-16(36)37)11-51-57(48,49)54-56(46,47)50-10-14-20(53-55(43,44)45)19(39)25(52-14)34-13-33-18-22(28)31-12-32-23(18)34/h12-14,19-21,25,39-40,42H,4-11H2,1-3H3,(H,29,35)(H,30,41)(H,36,37)(H,46,47)(H,48,49)(H2,28,31,32)(H2,43,44,45)/t14-,19-,20-,21+,25-,27+/m1/s1 Key: CABVTRNMFUVUDM-VRHQGPGLBX;
	SMILES O=C(O)C[C@@](O)(C)CC(=O)SCCNC(=O)CCNC(=O)[C@H](O)C(C)(C)COP(=O)(O)OP(=O)(O)OC[C@H]3O[C@@H](n2cnc1c(ncnc12)N)[C@H](O)[C@@H]3OP(=O)(O)O;
Sifat
Rumus kimia	C27H44N7O20P3S
Massa molar	911,661 g/mol
	Kecuali dinyatakan lain, data di atas berlaku pada suhu dan tekanan standar (25 °C [77 °F], 100 kPa).
	verifikasi (apa ini ?)
	Referensi

β-Hidroksi β-metilglutaril-KoA (biasa disingkat HMG-KoA), juga dikenal sebagai 3-hidroksi-3-metilglutaril koenzim A, adalah zat antara dalam lintasan mevalonat dan ketogenesis. Zat ini terbentuk dari asetil-KoA dan asetoasetil KoA oleh HMG-KoA sintase. Penelitian Minor J. Coon dan Bimal Kumar Bachhawat pada tahun 1950-an di Universitas Illinois menghasilkan penemuannya.^[1]^[2]

HMG-KoA adalah perantara metabolik dalam metabolisme asam amino rantai cabang, yang meliputi leusina, isoleusina, dan valina.^[3] Prekursor langsungnya adalah β-metilglutakonil-CoA (MG-KoA) dan β-hidroksi β-metilbutiril-KoA (HMB-KoA).^[4]

HMG-KoA reduktase mengkatalisis konversi HMG-KoA menjadi asam mevalonat, suatu langkah penting dalam biosintesis kolesterol.

Lintasan mevalonat

Sintesis mevalonat dimulai dengan kondensasi Claisen yang dikatalisis oleh ketotiolase beta dari dua molekul asetil-KoA untuk menghasilkan asetoasetil KoA. Reaksi berikut melibatkan penggabungan asetil-KoA dan asetoasetil-KoA untuk membentuk HMG-KoA, suatu proses yang dikatalisis oleh HMG-KoA sintase.^[5]

Pada langkah terakhir biosintesis mevalonat, HMG-KoA reduktase, suatu oksidoreduktase yang bergantung pada NADPH, mengkatalisis konversi HMG-KoA menjadi mevalonat, yang merupakan titik regulasi utama dalam lintasan ini. Mevalonat berfungsi sebagai prekursor kelompok isoprenoid yang dimasukkan ke dalam berbagai macam produk akhir, termasuk kolesterol pada manusia.^[6]

Lintasan ketogenesis

HMG-CoA liase memecahnya menjadi asetil-KoA dan asetoasetat.

Referensi

^ Sarkar DP (2015). "Classics in Indian Medicine" (PDF). The National Medical Journal of India (28): 3. Diarsipkan dari asli (PDF) tanggal 2016-05-31.
^ Surolia A (1997). "An outstanding scientist and a splendid human being". Glycobiology. 7 (4): v–ix. doi:10.1093/glycob/7.4.453.
^ "Valine, leucine and isoleucine degradation - Reference pathway". Kyoto Encyclopedia of Genes and Genomes. Kanehisa Laboratories. 27 January 2016. Diakses tanggal 1 February 2018.
^ Zanchi 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).
^ Garrett RH (2013). Biochemistry. Cengage Learning. hlm. 856. ISBN 978-1-305-57720-6.
^ Haines BE, Steussy CN, Stauffacher CV, Wiest O (October 2012). "Molecular modeling of the reaction pathway and hydride transfer reactions of HMG-CoA reductase". Biochemistry. 51 (40): 7983–95. doi:10.1021/bi3008593. PMC 3522576. PMID 22971202.

Artikel bertopik biokimia ini adalah sebuah rintisan. Anda dapat membantu Wikipedia dengan mengembangkannya.

[Classics_in_Indian_Medicine-1] Sarkar DP (2015). "Classics in Indian Medicine" (PDF). The National Medical Journal of India (28): 3. Diarsipkan dari asli (PDF) tanggal 2016-05-31.

[An_outstanding_scientist_and_a_splendid_human_being-2] Surolia A (1997). "An outstanding scientist and a splendid human being". Glycobiology. 7 (4): v–ix. doi:10.1093/glycob/7.4.453.

[HMG_biosynthesis-3] "Valine, leucine and isoleucine degradation - Reference pathway". Kyoto Encyclopedia of Genes and Genomes. Kanehisa Laboratories. 27 January 2016. Diakses tanggal 1 February 2018.

[HMB_athletic_performance-related_effects_2011_review-4] Zanchi 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).

[5] Garrett RH (2013). Biochemistry. Cengage Learning. hlm. 856. ISBN 978-1-305-57720-6.

[6] Haines BE, Steussy CN, Stauffacher CV, Wiest O (October 2012). "Molecular modeling of the reaction pathway and hydride transfer reactions of HMG-CoA reductase". Biochemistry. 51 (40): 7983–95. doi:10.1021/bi3008593. PMC 3522576. PMID 22971202.

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Ensiklopedia Dunia

MHG-KoA

Lintasan mevalonat

Lintasan ketogenesis

Referensi

Beranda

Program Studi