Isobutyryl coenzyme

Isobutyryl-coenzyme A (CoA) dehydrogenase deficiency (IBD deficiency) is a rare disorder in which the body is unable to process certain proteins properly. People with this disorder have inadequate levels of an enzyme that helps break down the amino acid valine, a building block of proteins. 

Mutations in the ACAD8 (http fghr.nlm.nih.gov/gene=acad8) gene cause isobutyryl-coenzyme A dehydrogenase deficiency. 

You may find the following resources about isobutyryl-coenzyme A dehydrogenase deficiency helpful. These materials are written for the general public. 

These sources were used to develop the Genetics Home Reference condition summary on isobutyryl-coenzyme A dehydrogenase deficiency. 

Isobutyryl-Coenzyme a Dehydrogenase Deficiency - Caused by Mutations in the ACAD8 Gene... 

Ratnatilleke A, JW Vrijbloed, JA Robinson (1999) Cloning and sequencing of the coenzyme B,2-binding domain of isobutyryl-CoA mutase from Streptomyces cinnamonensis. Reconstitution of mutase activity and characterization of the recombinant enzyme produced in Escherichia coli. J Biol Chem 274 31679-31685. 

About 10 coenzyme B -dependent enzymes are now known (reviewed in References 13,14, and 76 see Table 1) four carbon skeleton mutases (methylmalonyl-CoA mutase (MMCM), glutamate mutase (GM), methylene glu-tarate mutase (MGM), isobutyryl-CoA mutase (ICM) ), diol dehydratase (DD), glycerol dehydratase, ethanol-amine anunonia lyase (EAL), two amino mutases, and Bi2-dependent ribonucleotide reductase. The coenzyme Bi2-dependent enzymes are unevenly distributed in the living world, and MMCM is the only enzyme that is also indispensable in human metabolism. ... 

Vrilbloed JW, Zerbe-Brnkhardt K, Ratnatilleke A, Grubelnik-Leiser A, Robinson JA (1999) Insertional inactivation of methylmalonyl coenzyme A (CoA) mutase and isobutyryl-CoA mutase genes in Streptomyces cinnamonensis-. influence on polyketide antibiotic biosynthesis. J Bacteriol 181 5600 - 5605... 

Besides MMCM and GM, two other coenzyme B -dependent carbon skeleton mutases are known. These are (1) methylene glutarate mutase (MGM) from the anaerobe Eubacterium (Clostridium) barkeri, which catalyzes the equilibration of 2-methylene-glutarate with (R)-3-methylitaconate as part of a degradative path of nicotinic acid [175,199] and (2) isobutyryl-CoA mutase (ICM), which is observed in species of gram-positive bacteria Strep-tomyces and catalyzes the reversible rearrangement of iso-butyryl-CoA and n-butyryl-CoA [177]. The isomerization of iso-butyryl-CoA and n-butyryl-CoA in ICM is relevant in the biosynthesis of polyketide antibiotics [177]. 

MutQSes. Four enzymes are known that catalyze rearrangements of the carbon skeleton of the substrate molecules and which use adenosyl-cobamides (such as coenzyme B12 (2)) as their corrinoid cofactors (methylmalonyl-CoA mu-tase, glutamate mutase, a-methyleneglutarate mutase, and isobutyryl-CoA mu-tase see Table 1, entries 1-4) (10,62,63). Two adenosyl-cobamide-dependent enzymes catalyze the migration of an amino group in three substrate pairs... 

FIGURE 13.2 The role of BCAAs in energy metabolism. Following removal of their amino group by reversible transamination (a) and the irreversible decarboxylation of the resulting branched-chain a-keto acids to form coenzyme A (CoA) compounds (b), BCAAs act as precursors of acetyl CoA and tricarboxylic acid cycle intermediates. CoA-SH, reduced form of CoA IB-CoA, isobutyryl-CoA ILE, isoleucine IV-CoA, isovaleryl-CoA KIC, a-ketoiso-caproate KIV, a-ketoisovalerate KMV, a-keto-P-methylvalerate LEU, leucine MB-CoA, a-methylbutyryl-CoA NADHj, reduced nicotinamide adenine dinucleotide VAL, valine. 

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