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Miyamoto T, Fushinobu S, Saitoh Y, Sekine M, Katane M, Sakai-Kato K, Homma H. Novel tetrahydrofolate-dependent d-serine dehydratase activity of serine hydroxymethyltransferases. FEBS J 2024; 291:308-322. [PMID: 37700610 DOI: 10.1111/febs.16953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 08/12/2023] [Accepted: 09/06/2023] [Indexed: 09/14/2023]
Abstract
d-Serine plays vital physiological roles in the functional regulation of the mammalian brain, where it is produced from l-serine by serine racemase and degraded by d-amino acid oxidase. In the present study, we identified a new d-serine metabolizing activity of serine hydroxymethyltransferase (SHMT) in bacteria as well as mammals. SHMT is known to catalyze the conversion of l-serine and tetrahydrofolate (THF) to glycine and 5,10-methylenetetrahydrofolate, respectively. In addition, we found that human and Escherichia coli SHMTs have d-serine dehydratase activity, which degrades d-serine to pyruvate and ammonia. We characterized this enzymatic activity along with canonical SHMT activity. Intriguingly, SHMT required THF to catalyze d-serine dehydration and did not exhibit dehydratase activity toward l-serine. Furthermore, SHMT did not use d-serine as a substrate in the canonical hydroxymethyltransferase reaction. The d-serine dehydratase activities of two isozymes of human SHMT were inhibited in the presence of a high concentration of THF, whereas that of E. coli SHMT was increased. The pH and temperature profiles of d-serine dehydratase and serine hydroxymethyltransferase activities of these three SHMTs were partially distinct. The catalytic efficiency (kcat /Km ) of dehydratase activity was lower than that of hydroxymethyltransferase activity. Nevertheless, the d-serine dehydratase activity of SHMT was physiologically important because d-serine inhibited the growth of an SHMT deletion mutant of E. coli, ∆glyA, more than that of the wild-type strain. Collectively, these results suggest that SHMT is involved not only in l- but also in d-serine metabolism through the degradation of d-serine.
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Affiliation(s)
- Tetsuya Miyamoto
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Shinya Fushinobu
- Department of Biotechnology, The University of Tokyo, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Japan
| | - Yasuaki Saitoh
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Masae Sekine
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Masumi Katane
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Kumiko Sakai-Kato
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Hiroshi Homma
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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Arg-265: A critical residue of L.donovani cytosolic SHMT in maintaining the binding of THF and catalysis. Exp Parasitol 2015; 149:16-23. [DOI: 10.1016/j.exppara.2014.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Revised: 11/21/2014] [Accepted: 12/04/2014] [Indexed: 01/03/2023]
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3
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Cloning, DNA shuffling and expression of serine hydroxymethyltransferase gene from Escherichia coli strain AB90054. Enzyme Microb Technol 2007. [DOI: 10.1016/j.enzmictec.2006.05.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Schirch L. Serine hydroxymethyltransferase. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 53:83-112. [PMID: 7036682 DOI: 10.1002/9780470122983.ch3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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6
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Strísovský K, Jirásková J, Mikulová A, Rulísek L, Konvalinka J. Dual substrate and reaction specificity in mouse serine racemase: identification of high-affinity dicarboxylate substrate and inhibitors and analysis of the beta-eliminase activity. Biochemistry 2005; 44:13091-100. [PMID: 16185077 DOI: 10.1021/bi051201o] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mouse serine racemase (mSR) is a pyridoxal 5'-phosphate dependent enzyme that catalyzes the biosynthesis of the N-methyl-d-aspartate receptor coagonist d-serine in the brain. Furthermore, mSR catalyzes beta-elimination of serine and l-serine-O-sulfate into pyruvate. The biological significance of this beta-elimination activity and the factors influencing mSR substrate and reaction specificity, which are crucial for prospective inhibitor design, are poorly understood. Using a bacterial expression system and ATP-agarose affinity chromatography, we have generated a pure and active recombinant mSR and investigated its substrate and reaction specificity in vitro by analyzing a systematic series of compounds derived from l-Ser and l-serine-O-sulfate. The analysis revealed several competitive inhibitors of serine racemization including glycine (K(I) = 1.63 mM), several dicarboxylic acids including malonate (K(I) = 0.077 mM), and l-erythro-3-hydroxyaspartate (K(I) = 0.049 mM). The latter compound represents the most effective inhibitor of SR reported to date. A simple inversion of the beta-carbon configuration of the compound yields an excellent beta-elimination substrate l-threo-3-hydroxyaspartate. Inhibition analysis indicates that racemization and beta-elimination activities of mSR reside at the same active site. While the racemization activity is specific to serine, the beta-elimination activity has a broader specificity for l-amino acids with a suitable leaving group at the beta-carbon and optimal spatial orientation of the alpha-carboxyl and leaving groups. The possible implications of our observations for inhibitor design, regulation of activity, and function of mSR are discussed.
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Affiliation(s)
- Kvido Strísovský
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, Praha 6, 166 10, Czech Republic
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7
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He X, Agnihotri G, Liu Hw HW. Novel enzymatic mechanisms in carbohydrate metabolism. Chem Rev 2000; 100:4615-62. [PMID: 11749360 DOI: 10.1021/cr9902998] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- X He
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, Division of Medicinal Chemistry, College of Pharmacy, and Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712
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Ogawa H, Gomi T, Fujioka M. Serine hydroxymethyltransferase and threonine aldolase: are they identical? Int J Biochem Cell Biol 2000; 32:289-301. [PMID: 10716626 DOI: 10.1016/s1357-2725(99)00113-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Serine hydroxymethyltransferase, a pyridoxal phosphate-dependent enzyme, catalyses the interconversion of serine and glycine, both of which are major sources of one-carbon units necessary for the synthesis of purine, thymidylate, methionine, and so on. Threonine aldolase catalyzes the pyridoxal phosphate-dependent, reversible reaction between threonine and acetaldehyde plus glycine. No extensive studies have been carried out on threonine aldolase in animal tissues, and it has long been believed that serine hydroxymethyltransferase and threonine aldolase are the same, i.e. one entity. This is based on the finding that rabbit liver serine hydroxymethyltransferase possesses some threonine aldolase activity. Recently, however, many kinds of threonine aldolase and corresponding genes were isolated from micro-organisms, and these enzymes were shown to be distinct from serine hydroxymethyltransferase. The experiments with isolated hepatocytes and cell-free extracts from various animals revealed that threonine is degraded mainly through the pathway initiated by threonine 3-dehydrogenase, and there is little or no contribution by threonine aldolase. Thus, although serine hydroxymethyltransferase from some mammalian livers exhibits a low threonine aldolase activity, the two enzymes are distinct from each other and mammals lack the "genuine" threonine aldolase.
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Affiliation(s)
- H Ogawa
- Department of Biochemistry, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
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9
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Johnson AE, Tanner ME. Epimerization via carbon-carbon bond cleavage. L-ribulose-5-phosphate 4-epimerase as a masked class II aldolase. Biochemistry 1998; 37:5746-54. [PMID: 9548961 DOI: 10.1021/bi972984j] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Studies indicating that the E. coli L-ribulose-5-phosphate 4-epimerase employs an "aldolase-like" mechanism are reported. This NAD+-independent enzyme epimerizes a stereocenter that does not bear an acidic proton and therefore it cannot utilize a simple deprotonation-reprotonation mechanism. Sequence similarities between the epimerase and the class II l-fuculose-1-phosphate aldolase suggest that the two may be evolutionarily related and that the epimerization may occur via carbon-carbon bond cleavage and re-formation. Conserved residues thought to provide the metal ion ligands of the epimerase have been modified using site-directed mutagenesis. The resulting mutants show low kcat values in addition to a reduced affinity for Zn2+. These observations serve to establish that there is a structural link between between the active site geometry of the epimerase and the aldolase. In addition, the H97N mutant was found to catalyze the condensation of dihydroxyacetone and glycolaldehyde phosphate to produce a mixture of L-ribulose-5-phosphate and D-xylulose-5-phosphate. This observation of aldolase activity establishes that the epimerase active site is capable of promoting carbon-carbon bond cleavage. Furthermore, glycolaldehyde phosphate was shown to be a competitive inhibitor of the mutant enzyme (KI = 0.37 mM) but not of the wild-type enzyme. The mutation apparently causes the epimerase to become "leaky" and enables it to bind/generate the normal reaction intermediates from the unbound aldol cleavage products.
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Affiliation(s)
- A E Johnson
- Department of Chemistry, University of British Columbia, Vancouver, Canada
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Bhaskar B, Prakash V, Savithri HS, Rao NA. Interactions of L-serine at the active site of serine hydroxymethyltransferases: induction of thermal stability. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1209:40-50. [PMID: 7947980 DOI: 10.1016/0167-4838(94)90134-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Serine hydroxymethyltransferase (SHMT), EC 2.1.2.1, exhibits broad substrate and reaction specificity. In addition to cleaving many 3-hydroxyamino acids to glycine and an aldehyde, the enzyme also catalyzed the decarboxylation, transamination and racemization of several substrate analogues of amino acids. To elucidate the mechanism of interaction of substrates, especially L-serine with the enzyme, a comparative study of interaction of L-serine with the enzyme from sheep liver and Escherichia coli, was carried out. The heat stability of both the enzymes was enhanced in the presence of serine, although to different extents. Thermal denaturation monitored by spectral changes indicated an alteration in the apparent Tm of sheep liver and E. coli SHMTs from 55 +/- 1 degrees C to 72 +/- 3 degrees C at 40 mM serine and from 67 +/- 1 degrees C to 72 +/- 1 degrees C at 20 mM serine, respectively. Using stopped flow spectrophotometry k values of (49 +/- 5) x 10(-3) s-1 and (69 +/- 7) x 10(-3) s-1 for sheep liver and E. coli enzymes were determined at 50 mM serine. The binding of serine monitored by intrinsic fluorescence and sedimentation velocity measurements indicated that there was no generalized change in the structure of both proteins. However, visible CD measurements indicated a change in the asymmetric environment of pyridoxal 5'-phosphate at the active site upon binding of serine to both the enzymes. The formation of an external aldimine was accompanied by a change in the secondary structure of the enzymes monitored by far UV-CD spectra. Titration microcalorimetric studies in the presence of serine (8 mM) also demonstrated a single class of binding and the conformational changes accompanying the binding of serine to the enzyme resulted in a more compact structure leading to increased thermal stability of the enzyme.
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Affiliation(s)
- B Bhaskar
- Department of Biochemistry, Indian Institute of Science, Bangalore
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11
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Alexander FW, Sandmeier E, Mehta PK, Christen P. Evolutionary relationships among pyridoxal-5'-phosphate-dependent enzymes. Regio-specific alpha, beta and gamma families. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 219:953-60. [PMID: 8112347 DOI: 10.1111/j.1432-1033.1994.tb18577.x] [Citation(s) in RCA: 322] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Pyridoxal-5'-phosphate-dependent enzymes catalyze manifold reactions in the metabolism of amino acids. A comprehensive comparison of amino acid sequences has shown that most of these enzymes can be assigned to one of three different families of homologous proteins. The sequences of the enzymes of each family were aligned and their homology confirmed by profile analysis. Scrutiny of the reactions catalyzed by the enzymes showed that their affiliation with one of the three structurally defined families correlates in most cases with their regio-specificity. In the largest family, the covalency changes of the substrate occur at the same carbon atom that carries the amino group forming the imine linkage with the coenzyme. This family was thus named alpha family. It comprises glycine hydroxymethyltransferase, glycine C-acetyltransferase, 5-aminolevulinate synthase, 8-amino-7-oxononanoate synthase, all aminotransferases (with the possible exception of subgroup III), a number of other enzymes relatively closely related with the aminotransferases and very likely a certain group of amino acid decarboxylases as well as tryptophanase and tyrosine phenol-lyase which, however, catalyze beta-elimination reactions. The beta family includes L- and D-serine dehydratase, threonine dehydratase, the beta subunit of tryptophan synthase, threonine synthase and cysteine synthase. These enzymes catalyze beta-replacement or beta-elimination reactions. The gamma family incorporates O-succinylhomoserine (thiol-lyase, O-acetylhomoserine (thiol)-lyase, and cystathionine gamma-lyase, which catalyze gamma-replacement or gamma-elimination reactions, as well as cystathionine beta-lyase. The alpha and gamma family might be distantly related with one another, but are clearly not homologous with the beta family. Apparently, the primordial pyridoxal-5'-phosphate-dependent enzymes were regio-specific catalysts, which first specialized for reaction specificity and then for substrate specificity. The following pyridoxal-5'-phosphate-dependent enzymes seem to be unrelated with the alpha, beta or gamma family by the criterion of profile analysis:alanine racemase, selenocysteine synthase, and many amino acid decarboxylases. These enzymes may represent yet other families of B6 enzymes.
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Affiliation(s)
- F W Alexander
- Biochemisches Institut, Universität Zürich, Switzerland
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12
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Marcus JP, Dekker EE. Identity and some properties of the L-threonine aldolase activity manifested by pure 2-amino-3-ketobutyrate ligase of Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1164:299-304. [PMID: 8343529 DOI: 10.1016/0167-4838(93)90262-p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
2-Amino-3-ketobutyrate ligase catalyzes the reversible, pyridoxal 5'-phosphate-dependent condensation of glycine with acetyl CoA forming the unstable intermediate, 2-amino-3-ketobutyrate. Several independent lines of evidence indicate that the pure protein obtained in the purification of this ligase from Escherichia coli also has L-threonine aldolase activity. The evidence includes: (a), a constant ratio of specific activities (aldolase/ligase) at all stages of purifying 2-amino-3-ketobutyrate ligase to homogeneity; (b), the same rate of loss of aldolase and ligase activities during controlled heat inactivation of the pure protein at 60 degrees C in the absence, as well as in the presence of acetyl CoA, a protective substrate; (c), ratios of the two enzymatic activities that are not significantly different during slow inactivation by iodoacetamide, with and without L-threonine added; (d), coincident rates of loss and essentially identical rates of recovery of aldolase activity and ligase activity during resolution of the holoenzyme with hydroxylamine followed by reconstitution with pyridoxal 5'-phosphate. No aldolase activity is observed with D-threonine as substrate and L-allothreonine is about 25% as effective as L-threonine. Whereas ligase activity has a sharp pH optimum at 7.5, the aldolase activity of this pure protein is maximal at pH 9.0. Comparative apparent Km values for glycine (ligase) and L-threonine (aldolase) are 10 mM and 0.9 mM, respectively, whereas corresponding respective Vmax values were found to be 2.5 mumol of CoA released/min per mg vs. 0.014 mumol of acetaldehyde formed (NADH oxidized)/min per mg.
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Affiliation(s)
- J P Marcus
- Department of Biological Chemistry, University of Michigan, Ann Arbor
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13
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A novel intermediate in the interaction of thiosemicarbazide with sheep liver serine hydroxymethyltransferase. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41741-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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14
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Turner S, Ireland R, Morgan C, Rawsthorne S. Identification and localization of multiple forms of serine hydroxymethyltransferase in pea (Pisum sativum) and characterization of a cDNA encoding a mitochondrial isoform. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42243-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Arginine residues involved in binding of tetrahydrofolate to sheep liver serine hydroxymethyltransferase. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50421-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Smith DM, Thomas NR, Gani D. A comparison of pyridoxal 5'-phosphate dependent decarboxylase and transaminase enzymes at a molecular level. EXPERIENTIA 1991; 47:1104-18. [PMID: 1765122 DOI: 10.1007/bf01918374] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pyridoxal 5'-phosphate is a coenzyme for a number of enzymes which catalyse reactions at C alpha of amino acid substrates including transaminases, decarboxylases and serine hydroxymethyltransferase. Using the X-ray coordinates for a transaminase, aspartate aminotransferase, and the results of stereochemical and mechanistic studies for decarboxylases and serine hydroxymethyltransferase, an active-site structure for the decarboxylase group is constructed. The structure of the active-site is further refined through active-site pyridoxyllysine peptide sequence comparison and a 3-D catalytic mechanism for the L-alpha-amino acid decarboxylases is proposed. The chemistry of serine hydroxymethyltransferase is re-examined in the light of the proposed decarboxylase mechanism.
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Affiliation(s)
- D M Smith
- Department of Chemistry, University, St. Andrews, Fife, Scotland
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18
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Thomas NR, Gani D. Synthesis of (2R)- and (2S)- [1-13C]-2-amino-2-methylmalonic acid: Chiral substrates for serine hydroxymethyltransferase. Tetrahedron 1991. [DOI: 10.1016/s0040-4020(01)90505-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Purification and properties of serine hydroxymethyltransferase and C1-tetrahydrofolate synthase from L1210 cells. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38324-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Affiliation(s)
- A Meister
- Department of Biochemistry, Cornell University Medical College, New York, N.Y. 10021
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22
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Martini F, Maras B, Tanci P, Angelaccio S, Pascarella S, Barra D, Bossa F, Schirch V. The Primary Structure of Rabbit Liver Mitochondrial Serine Hydroxymethyltransferase. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)81821-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Shostak K, Schirch V. Serine hydroxymethyltransferase: mechanism of the racemization and transamination of D- and L-alanine. Biochemistry 1988; 27:8007-14. [PMID: 3069126 DOI: 10.1021/bi00421a006] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The reaction specificity and stereochemical control of Escherichia coli serine hydroxymethyltransferase were investigated with D- and L-alanine as substrates. An active-site H228N mutant enzyme binds both D- and L-alanine with Kd values of 5 mM as compared to 30 and 10 mM, respectively, for the wild-type enzyme. Both wild-type and H228N enzymes form quinonoid complexes absorbing at 505 nm by catalyzing the loss of the alpha-proton from both D- and L-alanine. Racemization and transamination reactions were observed to occur with both alanine isomers as substrates. The relative rates of these reactions are quinonoid formation greater than alpha-proton solvent exchange greater than racemization greater than transamination. The observation that the rate of quinonoid formation with either alanine isomer is an order of magnitude faster than solvent exchange suggests that the alpha-protons from both D- and L-alanine are transferred to base(s) on the enzyme. The rate of racemization is 2 orders of magnitude slower than the formation of the quinonoid complexes. This latter difference in rate suggests that the quinonoid complexes formed from D- and L-alanine are not identical. The difference in structure of the two quinonoid complexes is proposed to be the active-site location of the alpha-protons lost from the two alanine isomers, rather than two orientations of the pyridoxal phosphate ring. The results are consistent with a two-base mechanism for racemization.
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Affiliation(s)
- K Shostak
- Department of Biochemistry, Virginia Commonwealth University, Richmond 23298
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25
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Miyazaki SS, Toki S, Izumi Y, Yamada H. Purification and characterization of a serine hydroxymethyltransferase from an obligate methylotroph, Hyphomicrobium methylovorum GM2. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 162:533-40. [PMID: 3830156 DOI: 10.1111/j.1432-1033.1987.tb10672.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A serine hydroxymethyltransferase was purified to complete homogeneity from a serine-producing obligate methylotroph, Hyphomicrobium methylovorum GM2. The enzyme has a molecular mass of about 98 kDa and consists of two subunits of identical molecular mass. The holoenzyme exhibits absorption maxima at 280 nm, 340 nm and 415 nm in potassium phosphate buffer, pH 7.3, the last of which shifts with a change in pH (6.0-7.5) and contains 2 mol pyridoxal phosphate/mol enzyme. The holoenzyme is converted to the apoenzyme on incubation with phenylhydrazine and reconstituted on the addition of pyridoxal phosphate. The enzyme activity was inhibited on the addition of several sulfhydryl-modifying reagents and then recovered with 2-mercaptoethanol. One sulfhydryl group per subunit was found to be responsible for the activity. Isoelectric focusing showed that the enzyme has a pI of 5.6. The Km values for glycine, L-serine and DL-beta-phenylserine are 0.046 mM, 0.15 mM and 33 mM respectively.
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Abstract
It can be concluded on the base of data from literature and of our own results, that the metabolism of glycine is localized mainly in liver tissue. The main catabolic pathway of nutritional glycine proceeds via the glycine-cleavage enzyme, serinehydroxymethyltransferase and serinedehydratase or serine-pyruvate aminotransferase and via serine and pyruvate. The physiological significance of this metabolic pathway is estimated. The catabolism via the C1-pool is limited by the regeneration rate of tetrahydrofolic acid. Other pathways (via glyoxylate, SHEMIN-cycle, aminoacetone cycle) are only of minor significance for the catabolism of glycine originating from food.
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Akhtar M, Emery VC, Robinson JA. Chapter 9 Pyridoxal phosphate-dependent enzymic reactions: mechanism and stereochemistry. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/s0167-7306(08)60380-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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Mendelson IS. A strategy for glycine encephalopathy therapy. JOURNAL OF MENTAL DEFICIENCY RESEARCH 1982; 26 (Pt 2):107-110. [PMID: 6809951 DOI: 10.1111/j.1365-2788.1982.tb00134.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
An inherited defect in the glycine cleavage enzyme results in the condition of neonatal glycine encephalopathy which has not responded to the current innovative methods of therapy. A re-examination of the enzyme structure and metabolic pathways, leads us to recommend future clinical evaluation of (1) vitamin-responsiveness, e.g., pyridoxine, folate and lipoic acid, (2) methionine, (3) N5, N10-methylene tetrahydrofolate and (4) alpha-methylserine therapy during the critical period of neonatal brain growth and development.
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30
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Chapter 4 Stereochemistry of pyridoxal phosphate-catalyzed reactions. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/s0167-7306(08)60395-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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31
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Ramesh KS, Anantanarayanan VS, Rao NA. Allosteric serine hydroxymethyltransferase from monkey liver: Correlation of conformational changes caused by denaturants with the alterations in catalytic activity. J Biosci 1981. [DOI: 10.1007/bf02702660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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32
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Microspectrophotometric measurements on single crystals of mitochondrial serine hydroxymethyltransferase. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69521-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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33
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Hauschka PV, Henson EB, Gallop PM. Quantitative analysis and comparative decarboxylation of aminomalonic acid, beta-carboxyaspartic acid, and gamma-carboxyglutamic acid. Anal Biochem 1980; 108:57-63. [PMID: 7457858 DOI: 10.1016/0003-2697(80)90691-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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34
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Schirch L, Peterson D. Purification and properties of mitochondrial serine hydroxymethyltransferase. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)43903-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Maher TJ, Wurtman RJ. L-Threonine administration increases glycine concentrations in the rat central nervous system. Life Sci 1980; 26:1283-6. [PMID: 6770208 DOI: 10.1016/0024-3205(80)90086-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Schirch L, Slagel S, Barra D, Martini F, Bossa F. Evidence for a sulfhydryl group at the active site of serine transhydroxymethylase. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)85839-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Hansen J, Davis L. Serine hydroxymethylase. Specificity of bond cleaveage to form quinonoid intermediates and rate of holoenzyme formation. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 568:321-30. [PMID: 486486 DOI: 10.1016/0005-2744(79)90299-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
L-Serine transhydroxymethylase (5,10-methylenetetrahydrofolate:glycine hydroxymethyltransferase, EC 2.1.2.1) a pyridoxal phosphate-dependent enzyme, has been obtained as a homogeneous preparation with a specific activity of 6.7 mumol benzaldehyde per minute at 30 degrees C at pH 7.5 in N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (Hepes) buffer, with DL-threo-beta-phenylserine as a substrate. This enzyme has been used to study the specificity of bond cleavage in forming quinonoid intermediates from DL and non-asymmetric amino acids. The ability of the generated quinonoids to react with formaldehyde and acetaldehyde has also been studied and evidence obtained for formation of the corresponding beta-hydroxymethyl and beta-hydroxyethyl amino acid derivaties. Apotranshydroxymethylase has been prepared and the rate of holoenzyme formation was found to be 0.52 min-1 by measuring Schiff base formation at 425 nm and 0.66 min-1 as determined from restoration of enzymic activity. A requirement for the presence of mercaptoethanol for complete reactivation was also established by these studies.
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Zelikson R, Luzzati M. Mitochondrial and cytoplasmic distribution in Saccharmoyces cerevisiae of enzymes involved in folate-coenzyme-mediated one-carbon-group transfer. A genetic and biochemical study of the enzyme deficiencies in mutants tmp3 and ade3. EUROPEAN JOURNAL OF BIOCHEMISTRY 1977; 79:285-92. [PMID: 334546 DOI: 10.1111/j.1432-1033.1977.tb11808.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Bossa F, Barra D, Martini F, Schirch LV, Fasella P. Serine transhydroxymethylase from rabbit liver. Sequence of anonapeptide at the pyridoxal-5'-phosphate-binding site. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 70:397-401. [PMID: 1009937 DOI: 10.1111/j.1432-1033.1976.tb11029.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The amino acid sequence of the coenzyme-binding site of serine transhydroxymethylase from rabbit liver has been determined. After reduction with NaBH4 and aminoethylation, a first sample of enzyme was digested with thermolysin and a single phosphopyridoxyl peptide was isolated. A second sample of similarly treated enzyme was digested with chymotrypsin and three phosphopyridoxyl peptides clearly originating from a unique coenzyme-binding site were isolated. Sequence analysis of these peptides indicate the following structure: Val-Val-Thr-Thr-His(Pxy)-Thr-Leu. Sequence homologies of the active site of various pyridoxalphosphate enzymes are discussed in terms of a possible catalytic role and of evolution of this class of proteins.
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Cybulski RL, Fisher RR. Intramitochondrial localization and proposed metabolic significance of serine transhydroxymethylase. Biochemistry 1976; 15:3183-7. [PMID: 952851 DOI: 10.1021/bi00660a004] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Serine transhydroxymethylase is a latent enzyme of intact rat liver mitochondria. The enzyme is neither solubilized by the selective removal of the outer membrane with digitonin, nor inactivated by concentrations of diazobenzenesulfonate that do not penetrate the inner membrane, but that do inhibit solubilized serine transhydroxymethylase. Swelling of mitochondria was studied in isoosmotic solutions of substrates under conditions that would define transport as neutral uniport, anion-hydroxyl exchange, anion-anion exchange, or electrophoretic. L-Serine and glycine appear to be rapidly taken up by a nonelectrophoretic uniport mechanism, while folate and tetrahydrofolate are not tranported. The results localize the enzyme in the matrix and indicate that the latent activity results from a lack of tetrahydrofolate transport across the inner membrane. Based on these results, the dual localization of serine transhydroxymethylase in the mitochondria and the cytosol is proposed to provide a one-carbon shuttle system to link one-carbon metabolism in the two-cellular compartments.
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Shimojo T, Akino T, Miura Y, Schroepfer GJ. Sphingolipid base metabolism. Stereospecific uptake of proton in the enzymatic conversion of sphinganine 1-phosphate to ethanolamine 1-phosphate. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(17)33317-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Zelikson R, Luzzati M. Two forms of serine transhydroxymethylase, one absent in a thymidylate-less mutant in Saccharomyces cerevisiae. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 64:7-13. [PMID: 6271 DOI: 10.1111/j.1432-1033.1976.tb10269.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Schirch L. Serine transhydroxymethylase. Relaxation and transient kinetic study of the formation and interconversion of the enzyme-glycine complexes. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41786-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Copper AJ, Meister A. Enzymatic conversion of O-carbamyl-L-serine to pyruvate and ammonia. Biochem Biophys Res Commun 1973; 55:780-7. [PMID: 4761084 DOI: 10.1016/0006-291x(73)91212-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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46
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