Biotina

Archives of Medical Research 33 (2002) 439–447

REVIEW ARTICLE

Biotin in Metabolism and Its Relationship to Human Disease
Diana Pacheco-Alvarez, R. Sergio Solórzano-Vargas and Alfonso León Del Río
Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas (IIBM), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico Received for publication January 2, 2002; accepted April 17, 2002 (02/001).

Biotin, a water-soluble vitamin, is used as cofactor of enzymes involved in carboxylation reactions. In humans, there are five biotin-dependent carboxylases: propionyl-CoA carboxylase; methylcrotonyl-CoA carboxylase; pyruvate carboxylase, and two forms of acetylCoA carboxylase. These enzymes catalyze key reactions in gluconeogenesis, fatty acid metabolism, and amino acid catabolism; thus, biotin plays an essential role in maintaining metabolic homeostasis. In recent years, biotin has been associated with several diseases in humans. Some are related to enzyme deficiencies involved in biotin metabolism. However, not all biotin-responsive disorders can be explained based on the classical role of the vitamin in cell metabolism. Several groups have suggested that biotin may be involved in regulating transcription or protein expression of different proteins. Biotinylation of histones and triggering of transduction signaling cascades have been suggested as underlying mechanisms behind these non-classical biotin-deficiency manifestation in humans. © 2002 IMSS. Published by Elsevier Science Inc.
Key Words: Biotin, Holocarboxylase synthetase, Biotin deficiency, Multiple carboxylase deficiency.

Introduction Biotin is a water-soluble vitamin found in all organisms that functions as cofactor of enzymes known as biotin-dependent carboxylases (1). The role of biotin in carboxylases is to act as vector for carboxyl-group transfer between donor and acceptor molecules during carboxylation reaction. Covalent addition of biotin to these