Carnitine biosynthesis: identification of the cDNA encoding human gamma-butyrobetaine hydroxylase.
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Vaz FM, van Gool S, Ofman R, Ijlst L, Wanders RJ
Carnitine biosynthesis: identification of the cDNA encoding human gamma-butyrobetaine hydroxylase.
Biochem Biophys Res Commun. 1998 Sep 18;250(2):506-10.
- PubMed ID
- 9753662 [ View in PubMed]
- Abstract
gamma-Butyrobetaine hydroxylase (EC 1.14.11.1) is the last enzyme in the biosynthetic pathway of L-carnitine and catalyzes the formation of L-carnitine from gamma-butyrobetaine, a reaction dependent on alpha-ketoglutarate, Fe2+, and oxygen. We report the purification of the protein from rat liver to apparent homogeneity, which allowed N-terminal sequencing using Edman degradation. The obtained amino acid sequence was used to screen the expressed sequence tag database and led to the identification of a human cDNA containing an open reading frame of 1161 base pairs encoding a polypeptide of 387 amino acids with a predicted molecular weight of 44.7 kDa. Heterologous expression of the open reading frame in the yeast Saccharomyces cerevisiae confirmed that the cDNA encodes the human gamma-butyrobetaine hydroxylase. Northern blot analysis showed gamma-butyrobetaine hydroxylase expression in kidney (high), liver (moderate), and brain (very low), while no expression could be detected in the other investigated tissues.