Identification and characterisation of human aldose 1-epimerase.
Aldose 1-epimerase or mutarotase (EC 5.1.3.3) is a key enzyme of carbohydrate metabolism catalysing the interconversion of the alpha- and beta-anomers of hexose sugars such as glucose and galactose. We identified an open reading frame in the human genome (BC014916) which has high sequence similarity to previously identified bacterial aldose 1-epimerases. This sequence was cloned into a bacterial expression vector, and expressed and purified from this source. Enzyme assays show that the protein has aldose 1-epimerase activity and exhibits a preference for galactose over glucose. Site-directed mutagenesis confirmed the involvement of three residues involved in catalysis and substrate binding.
Timson
David J
DJ
School of Biological Sciences, The University of Manchester, 2.205 Stopford Building, Oxford Road, M13 9PT, Manchester, UK.
Reece
Richard J
RJ
D000595:Amino Acid Sequence; D002238:Carbohydrate Epimerases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D003001:Cloning, Molecular; D005690:Galactose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity
D011993:Recombinant Fusion Proteins; D002238:Carbohydrate Epimerases; C019646:aldose 1-epimerase; D005947:Glucose; D005690:Galactose