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Properties of human and rabbit cytosolic serine hydroxymethyltransferase are changed by single nucleotide polymorphic mutations.
Arch Biochem Biophys. 2005 Oct 01; 442(1):92-101.AB

Abstract

Serine hydroxymethyltransferase (SHMT) is a key enzyme in the formation and regulation of the folate one-carbon pool. Recent studies on human subjects have shown the existence of two single nucleotide polymorphisms that may be associated with several disease states. One of these mutations results in Ser394 being converted to an Asn (S394N) and the other in the change of Leu474 to a Phe (L474F). These mutations were introduced into the cDNA for both human and rabbit cytosolic SHMT and the mutant enzymes expressed and purified from an Escherichia coli expression system. The mutant enzymes show normal values for kcat and Km for serine. However, the S394N mutant enzyme has increased dissociation constant values for both glycine and tetrahydrofolate (tetrahydropteroylglutamate) and its pentaglutamate form compared to wild-type enzyme. The L474F mutant shows lowered affinity (increased dissociation constant) for only the pentaglutamate form of the folate ligand. Both mutations result in decreased rates of pyridoxal phosphate addition to the mutant apo enzymes to form the active holo enzymes. Neither mutation significantly affects the stability of SHMT or the rate at which it converts 5,10-methenyl tetrahydropteroyl pentaglutamate to 5-formyl tetrahydropteroyl pentaglutamate. Analysis of the structures of rabbit and human SHMT show how mutations at these two sites can result in the observed functional differences.

Authors+Show Affiliations

Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, College of Medicine, Tainan 701, Taiwan. tffu@mail.ncku.edu.twNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

16137637

Citation

Fu, Tzu-Fun, et al. "Properties of Human and Rabbit Cytosolic Serine Hydroxymethyltransferase Are Changed By Single Nucleotide Polymorphic Mutations." Archives of Biochemistry and Biophysics, vol. 442, no. 1, 2005, pp. 92-101.
Fu TF, Hunt S, Schirch V, et al. Properties of human and rabbit cytosolic serine hydroxymethyltransferase are changed by single nucleotide polymorphic mutations. Arch Biochem Biophys. 2005;442(1):92-101.
Fu, T. F., Hunt, S., Schirch, V., Safo, M. K., & Chen, B. H. (2005). Properties of human and rabbit cytosolic serine hydroxymethyltransferase are changed by single nucleotide polymorphic mutations. Archives of Biochemistry and Biophysics, 442(1), 92-101.
Fu TF, et al. Properties of Human and Rabbit Cytosolic Serine Hydroxymethyltransferase Are Changed By Single Nucleotide Polymorphic Mutations. Arch Biochem Biophys. 2005 Oct 1;442(1):92-101. PubMed PMID: 16137637.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Properties of human and rabbit cytosolic serine hydroxymethyltransferase are changed by single nucleotide polymorphic mutations. AU - Fu,Tzu-Fun, AU - Hunt,Sharyn, AU - Schirch,Verne, AU - Safo,Martin K, AU - Chen,Bing-Hung, PY - 2005/06/14/received PY - 2005/07/20/revised PY - 2005/07/21/accepted PY - 2005/9/3/pubmed PY - 2005/12/13/medline PY - 2005/9/3/entrez SP - 92 EP - 101 JF - Archives of biochemistry and biophysics JO - Arch. Biochem. Biophys. VL - 442 IS - 1 N2 - Serine hydroxymethyltransferase (SHMT) is a key enzyme in the formation and regulation of the folate one-carbon pool. Recent studies on human subjects have shown the existence of two single nucleotide polymorphisms that may be associated with several disease states. One of these mutations results in Ser394 being converted to an Asn (S394N) and the other in the change of Leu474 to a Phe (L474F). These mutations were introduced into the cDNA for both human and rabbit cytosolic SHMT and the mutant enzymes expressed and purified from an Escherichia coli expression system. The mutant enzymes show normal values for kcat and Km for serine. However, the S394N mutant enzyme has increased dissociation constant values for both glycine and tetrahydrofolate (tetrahydropteroylglutamate) and its pentaglutamate form compared to wild-type enzyme. The L474F mutant shows lowered affinity (increased dissociation constant) for only the pentaglutamate form of the folate ligand. Both mutations result in decreased rates of pyridoxal phosphate addition to the mutant apo enzymes to form the active holo enzymes. Neither mutation significantly affects the stability of SHMT or the rate at which it converts 5,10-methenyl tetrahydropteroyl pentaglutamate to 5-formyl tetrahydropteroyl pentaglutamate. Analysis of the structures of rabbit and human SHMT show how mutations at these two sites can result in the observed functional differences. SN - 0003-9861 UR - https://www.unboundmedicine.com/medline/citation/16137637/Properties_of_human_and_rabbit_cytosolic_serine_hydroxymethyltransferase_are_changed_by_single_nucleotide_polymorphic_mutations_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0003-9861(05)00312-7 DB - PRIME DP - Unbound Medicine ER -