Information on EC 2.1.1.2 - guanidinoacetate N-methyltransferase

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The expected taxonomic range for this enzyme is: Chordata

EC NUMBER
COMMENTARY
2.1.1.2
-
RECOMMENDED NAME
GeneOntology No.
guanidinoacetate N-methyltransferase
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
S-adenosyl-L-methionine + guanidinoacetate = S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
S-adenosyl-L-methionine + guanidinoacetate = S-adenosyl-L-homocysteine + creatine
show the reaction diagram
mechanism
P10868
S-adenosyl-L-methionine + guanidinoacetate = S-adenosyl-L-homocysteine + creatine
show the reaction diagram
the hybrid density functional theory (DFT) method B3LYP is used to examine the reaction mechanism: The methyl group transfer from S-adenosylmethionine to NE of guanidinoacetate occurs concertedly with a proton transfer from NE to the neighboring OD1 of Asp134.
-
S-adenosyl-L-methionine + guanidinoacetate = S-adenosyl-L-homocysteine + creatine
show the reaction diagram
computer model of the reaction mechanism: by self-consistent-charge density functional tight binding/molecular mechanics, the bond lengths in the concerted mechanisms transition state is 1.26 A for both the OD1 (Asp-134)-HE (guanidinoacetate) and HE (guanidinoacetate)-NE (guanidinoacetate) bonds, and 2.47 and 2.03 A for the S8 (S-adenosyl-L-methionine)-C9 (S-adenosyl-L-methionine) and C9 (S-adenosyl-L-methionine)-NE (guanidinoacetate) bonds, respectively. The potential-energy barrier (delta E++) determined by single-point B3LYP/6-31+G*//MM is 18.9 kcal/mol. The contributions of the entropy (-TdeltaS++) and zero-point energy corrections delta(ZPE)++ by normal mode analysis are 2.3 kcal/mol and -1.7 kcal/mol, respectively. The activation enthalpy of this concerted mechanism is deltaH++ = 17.2 kcal/mol. The calculated free-energy barrier for the concerted mechanism is deltaG++ = 19.5 kcal/mol.
-
REACTION TYPE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
methyl group transfer
-
-
-
-
methyl group transfer
-
-
methyl group transfer
-
-
PATHWAY
KEGG Link
MetaCyc Link
Arginine and proline metabolism
-
creatine biosynthesis
-
Glycine, serine and threonine metabolism
-
Metabolic pathways
-
SYSTEMATIC NAME
IUBMB Comments
S-adenosyl-L-methionine:N-guanidinoacetate methyltransferase
-
SYNONYMS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
GA methylpherase
-
-
-
-
GAA methlytransferase
-
-
GAA methyltransferase
-
-
GAMT
Q14353
-
GAMT
-
-
guanidinoacetate methyltransferase
-
-
-
-
guanidinoacetate methyltransferase
-
-
guanidinoacetate methyltransferase
Q3S316
-
guanidinoacetate methyltransferase
-
-
guanidinoacetate methyltransferase
-
-
guanidinoacetate methyltransferase
-
-
guanidinoacetate methyltransferase
-
-
guanidinoacetate N-methyltransferase
-
-
guanidinoacetate transmethylase
-
-
-
-
guanidoacetate methyltransferase
-
-
-
-
methionine-guanidinoacetic transmethylase
-
-
-
-
N-guanidinoacetate methyltransferase
-
-
S-adenosyl-L-methionine:N-guanidinoacetate methyltransferase
Q3S316
-
CAS REGISTRY NUMBER
COMMENTARY
9029-75-8
-
ORGANISM
COMMENTARY
LITERATURE
SEQUENCE CODE
SEQUENCE DB
SOURCE
spiny mouse
-
-
Manually annotated by BRENDA team
13 years old, female, L197P transition on exon 6 of the guanidinoacetate N-methyltransferase gene
-
-
Manually annotated by BRENDA team
fibroblast cell line
SwissProt
Manually annotated by BRENDA team
expressed in Escherichia coli
-
-
Manually annotated by BRENDA team
recombinant enzyme
SwissProt
Manually annotated by BRENDA team
recombinant enzyme truncated at amino acid 37 from N-terminus
-
-
Manually annotated by BRENDA team
recombinant protein
SwissProt
Manually annotated by BRENDA team
Sprague-Dawley, 12.5, 15.5 and 18.5 days of gestation
SwissProt
Manually annotated by BRENDA team
; 7 to 8-d-old piglets, milk from lactating sows
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
malfunction
-
GAMT-deficient patients have strongly decreased levels of creatine in cerebrospinal fluid but are able to import creatine from the blood
malfunction
-
GAMT-cerebrospinal fluid knockout mice show decreased levels of creatine within their brain, which however still reach 1.4 mM or 0.4-0.5 mol/g of tissue, and a very significant increase in guanidinoacetate (1.9 mol/g tissue), GAMT knockout mice slowly replenish their brain creatine upon creatine treatment
malfunction
-
loss of GAMT causes a creatine deficiency syndrome that is characterized by neurological and motor dysfunction as well as developmental delay/regression, mental retardation, and related defects
physiological function
-
creatine synthesis
physiological function
-
GAMT is not only involved in p53-dependent apoptosis in response to genotoxic stress but is important for apoptosis induced by glucose deprivation
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
P10868
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
ir
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
P10868
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
Q3S316
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
S-adenosyl-L-methionine is the only possible methyl donor
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
biosynthesis of creatine
-
?
S-adenosyl-L-methionine + guanidinoacetic acid + glutathione
?
show the reaction diagram
-
assay at pH 7.4, 37C, 1 h, reaction stopped with 5% trichloroacetic acid
-
-
?
additional information
?
-
-
together with creatine/phosphocreatine shuttle system involved in brain energy homeostasis through a neuron-glial relationship
-
-
-
additional information
?
-
-
since the L197P mutation in the exon 6 of the guanidinoacetate N-methyltransferase gene leaves the isoform B of the enzyme unaffected, the occurrence of biochemical alterations and disease in this subject testifies against the possibility that isoform B has guanidinoacetate N-methyltransferase activity
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
P10868
-
-
?
S-adenosyl-L-methionine + guanidinoacetate
S-adenosyl-L-homocysteine + creatine
show the reaction diagram
-
biosynthesis of creatine
-
?
additional information
?
-
-
together with creatine/phosphocreatine shuttle system involved in brain energy homeostasis through a neuron-glial relationship
-
-
-
COFACTOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
METALS and IONS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
INHIBITORS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
3-deaza-S-adenosyl-L-homocysteine
-
competitive with S-adenosylmethionine
3-deaza-S-adenosyl-L-homocysteine
-
-
DTNB
-
2 mol DTNB per mol enzyme causes complete inactivation
glutathione
-
oxidized form, S-adenosylmethionine protects against inactivation
glutathione
-
readily reactivated by reduced glutathione, substrates do not protect against inactivation, guanidinoacetate together with sinefungin protects against inactivation, can be reactivated with thiol compounds
guanidine
P10868
-
N-ethylmaleimide
-
irreversible
p-chloromercuribenzoate
-
complete inhibition at 1 mM, reversible by addition of glutathione
S-adenosyl-L-homocysteine
-
competitive with S-adenosylmethionine
S-adenosyl-L-homocysteine
-
-
S-adenosyl-L-homocysteine
-
competitive with S-adenosylmethionine
S-adenosylhomocysteine
P10868
-
Sinefungin
-
competitive with S-adenosylmethionine
Sinefungin
-
competitive with S-adenosylmethionine
additional information
-
complete and irreversible inactivation by ultraviolet irradiation
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
2-mercaptoethanol
-
-
dithiothreitol
-
-
glutathione
-
required for maximum activity, can be replaced by other reducing agents
glutathione
-
required for maximum activity, can be replaced by other reducing agents
additional information
-
hepatic GAMT activity does not differ between rats fed creatine-free or creatine-supplemented diets
-
KM VALUE [mM]
KM VALUE [mM] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.011
-
Guanidinoacetate
-
wild type enzyme
0.013
-
Guanidinoacetate
P10868
mutant E45Q
0.022
-
Guanidinoacetate
P10868
mutant E45D
0.027
-
Guanidinoacetate
-
-
0.031
-
Guanidinoacetate
-
native enzyme
0.032
-
Guanidinoacetate
-
recombinant enzyme
0.05
-
Guanidinoacetate
P10868
wild-type
0.098
-
Guanidinoacetate
-
-
0.002
-
S-adenosyl-L-methionine
P10868
wild-type
0.003
-
S-adenosyl-L-methionine
-
native enzyme; recombinant enzyme
0.0042
-
S-adenosyl-L-methionine
P10868
mutant E45D
0.005
-
S-adenosyl-L-methionine
-
wild type enzyme
0.007
-
S-adenosyl-L-methionine
-
-
0.007
-
S-adenosyl-L-methionine
-
wild type enzyme
0.0088
-
S-adenosyl-L-methionine
P10868
mutant E45Q
0.024
-
S-adenosyl-L-methionine
P10868
mutant Y221F
0.049
-
S-adenosyl-L-methionine
-
-
2.3
-
Guanidinoacetate
P10868
mutant Y221F
additional information
-
additional information
-
all mutant enzymes listed with Km
-
TURNOVER NUMBER [1/s]
TURNOVER NUMBER MAXIMUM[1/s]
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.0788
-
Guanidinoacetate
-
wild type enzyme
1
-
S-adenosyl-L-methionine
P10868
mutant E45Q
2.1
-
S-adenosyl-L-methionine
P10868
mutant Y221F
2.4
-
S-adenosyl-L-methionine
P10868
mutant E45D
3.8
-
S-adenosyl-L-methionine
P10868
wild-type
0.081
-
Guanidinoacetate
-
wild type enzyme
additional information
-
additional information
-
all mutant enzymes listed with turnover
-
Ki VALUE [mM]
Ki VALUE [mM] Maximum
INHIBITOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.039
-
3-deaza-S-adenosyl-L-homocysteine
-
-
0.016
-
adenosylhomocysteine
-
-
0.0004
-
S-adenosyl-L-homocysteine
-
-
0.006
-
Sinefungin
-
-
0.018
-
Sinefungin
-
-
SPECIFIC ACTIVITY [µmol/min/mg]
SPECIFIC ACTIVITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
0.00035
-
-
brain
0.0005
-
-
liver of sarcoma-bearing mice
0.00053
-
-
S180 cell
0.00057
-
-
Ehrlich ascites carcinoma cell
0.0006
-
-
liver of normal mice; sarcoma
0.0007
-
-
intestine
0.00084
-
-
muscle
0.0019
-
-
kidney
0.0058
-
-
pancreas
0.022
-
-
purified enzyme
0.0286
-
-
liver
0.12
-
-
native enzyme
0.13
-
-
recombinant enzyme
0.16
-
-
purified enzyme
27.2
-
-
purified enzyme
additional information
-
-
nonradioactive method for measuring enzyme activity in lymphoblasts by using HPLC with UV detector
additional information
-
-
L197P transition in exon 6 reduces activity to 0.03 nMol creatine/mg/h, activity is assessed in lymphoblasts
additional information
-
Q14353
stable transfection of primary guanidinoacetate N-methyltransferase-deficient fibroblasts with pEGFP-guanidinoacetate N-methyltransferase results in the restoration of guanidinoacetate N-methyltransferase activity to 501 pmol creatine/mg/h from original 1 pmol creatine/mg/h. A 56fold increased guanidinoacetate N-methyltransferase activity is detected in transfected HeLa cells (7700 pmol creatine/mg/h vs. original 137 pmol creatine/mg/h).
pH OPTIMUM
pH MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
7.4
-
-
assay at
TEMPERATURE OPTIMUM
TEMPERATURE OPTIMUM MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
37
-
-
assay at
SOURCE TISSUE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
SOURCE
Q3S316
weak GAMT expression is detected in the epithelium of alimentary tract
Manually annotated by BRENDA team
-
L197P mutation in exon 6: guanidinoacetate increases to 33.6 microMol/l, creatine decreases to 24 microMol/l
Manually annotated by BRENDA team
-
all parts of brain, neurons and glia, very low levels in astrocytes
Manually annotated by BRENDA team
-
high expression in oligodendrocytes and olfactory ensheathing glia, moderate expression in astrocytes, low expression in neurons and microglia
Manually annotated by BRENDA team
P10868
in embryos at 15.5 days of gestation guanidinoacetate N-methyltransferase is detectable in pons and striatum. In embryos at 18.5 days of gestation guanidinoacetate N-methyltransferase is detectable in neocortex, hippocampus, striatum, pallidum and spinal cord. Non-radioactive in situ hybridization (58C for 40 h in 5 x SSC, 50% formamide and 40 microg/ml salmon sperm DNA) with digoxigenin-labeled antisense and sense riboprobes (400 ng/ml) for rat guanidinoacetate N-methyltransferase. guanidinoacetate N-methyltransferase proteins are detected with rabbit polyclonal antibodies
Manually annotated by BRENDA team
-
expressed within the brain, both during development and in adulthood
Manually annotated by BRENDA team
-
; low activity
Manually annotated by BRENDA team
-
highest enzyme level
Manually annotated by BRENDA team
-
low enzyme level
Manually annotated by BRENDA team
P10868
in embryos at 12.5 days of gestation guanidinoacetate N-methyltransferase is detectable in the hepatic primordium only, with all other tissues being negative. Non-radioactive in situ hybridization (58C for 40 h in 5 x SSC, 50% formamide and 40 microg/ml salmon sperm DNA) with digoxigenin-labeled antisense and sense riboprobes (400 ng/ml) for rat guanidinoacetate N-methyltransferase. guanidinoacetate N-methyltransferase proteins are detected with rabbit polyclonal antibodies
Manually annotated by BRENDA team
P10868
in embryos at 18.5 days of gestation guanidinoacetate N-methyltransferase is detectable. Non-radioactive in situ hybridization (58C for 40 h in 5 x SSC, 50% formamide and 40 microg/ml salmon sperm DNA) with digoxigenin-labeled antisense and sense riboprobes (400 ng/ml) for rat guanidinoacetate N-methyltransferase. guanidinoacetate N-methyltransferase proteins are detected with rabbit polyclonal antibodies
Manually annotated by BRENDA team
-
low activity
Manually annotated by BRENDA team
-
low enzyme level
Manually annotated by BRENDA team
-
; low activity
Manually annotated by BRENDA team
-
higher levels in female than in male
Manually annotated by BRENDA team
P10868
in embryos at 15.5 and 18.5 days of gestation guanidinoacetate N-methyltransferase is detectable in liver. Non-radioactive in situ hybridization (58C for 40 h in 5 x SSC, 50% formamide and 40 microg/ml salmon sperm DNA) with digoxigenin-labeled antisense and sense riboprobes (400 ng/ml) for rat guanidinoacetate N-methyltransferase. guanidinoacetate N-methyltransferase proteins are detected with rabbit polyclonal antibodies
Manually annotated by BRENDA team
-
highly active in the liver
Manually annotated by BRENDA team
-
; high activity
Manually annotated by BRENDA team
-
L197P mutation in exon 6, reduces the activity of guanidinoacetate N-methyltransferase
Manually annotated by BRENDA team
-
low enzyme level
Manually annotated by BRENDA team
-
low activity
Manually annotated by BRENDA team
Q3S316
GAMT is strongly expressed in all neurons and glia cells of neural cord
Manually annotated by BRENDA team
-
low enzyme level
Manually annotated by BRENDA team
P10868
in embryos at 15.5 and 18.5 days of gestation guanidinoacetate N-methyltransferase is detectable in pancreas. Non-radioactive in situ hybridization (58C for 40 h in 5 x SSC, 50% formamide and 40 microg/ml salmon sperm DNA) with digoxigenin-labeled antisense and sense riboprobes (400 ng/ml) for rat guanidinoacetate N-methyltransferase. guanidinoacetate N-methyltransferase proteins are detected with rabbit polyclonal antibodies
Manually annotated by BRENDA team
-
; the piglet pancreatic GAMT activity is only 1% of that found in the liver
Manually annotated by BRENDA team
P10868
in embryos at 18.5 days of gestation guanidinoacetate N-methyltransferase is detectable. Non-radioactive in situ hybridization (58C for 40 h in 5 x SSC, 50% formamide and 40 microg/ml salmon sperm DNA) with digoxigenin-labeled antisense and sense riboprobes (400 ng/ml) for rat guanidinoacetate N-methyltransferase. guanidinoacetate N-methyltransferase proteins are detected with rabbit polyclonal antibodies
Manually annotated by BRENDA team
-
hind leg muscle
Manually annotated by BRENDA team
-
mainly found in Sertoli cells of seminiferous tubules
Manually annotated by BRENDA team
-
L197P mutation in exon 6: guanidinoacetate increases to 2566 microMol/l, creatine decreases to 3.7 microMol/l
Manually annotated by BRENDA team
-
low enzyme level
Manually annotated by BRENDA team
additional information
-
absent in brain, small intestine, seminal vesicle, lung, vas deferens, cauda epididymis, coagulating gland and spleen
Manually annotated by BRENDA team
additional information
P10868
guanidinoacetate N-methyltransferase can not be detected in kidney of embryos of 12.5, 15.5 and 18.5 days of gestation. Non-radioactive in situ hybridization (58C for 40 h in 5 x SSC, 50% formamide and 40 microg/ml salmon sperm DNA) with digoxigenin-labeled antisense and sense riboprobes (400 ng/ml) for rat guanidinoacetate N-methyltransferase. guanidinoacetate N-methyltransferase proteins are detected with rabbit polyclonal antibodies
Manually annotated by BRENDA team
additional information
-
not expressed in microcapillary endothelial cells
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
Q3S316
GAMT is only located in the cytoplasm of epithelial cells but not in nuclei
Manually annotated by BRENDA team
-
perinuclear localization
Manually annotated by BRENDA team
MOLECULAR WEIGHT
MOLECULAR WEIGHT MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25000
-
-
gel filtration
25000
-
-
SDS-PAGE
26000
-
-
SDS-PAGE, in presence and absence of SDS
26000
-
-
SDS-PAGE, gel filtration
31000
-
-
SDS-PAGE, native PAGE without SDS yields heterogeneity in molecular weight
31000
-
-
SDS-PAGE
31500
-
-
gel filtration
60000
-
Q14353
Western Blot analyses shows the presences of the guanidinoacetate N-methyltransferase-EGFP fusion protein
SUBUNITS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
dimer
-
crystallization data
monomer
-
SDS-PAGE, gel filtration
Crystallization/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
in complex with S-adenosyl-L-methionine in monoclinic and tetragonal modification
-
in complex with S-adenosylhomocysteine and guanidinoacetate, and in complex with S-adenosyl-homocysteine and guanidine
P10868
TEMPERATURE STABILITY
TEMPERATURE STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
4
-
-
remains active for 24 h
GENERAL STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
inactivated during purification, can be reactivated by addition of a thiol
-
STORAGE STABILITY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
-50C, cell homogenate, enzyme activity is stable for at least 6 months
-
-20C, 10 mM phosphate buffer, pH 7.2, 1 mM EDTA, 0.1 M NaCl, concentrated by ultrafiltration
-
-60C, purified enzyme, stable for months
-
Purification/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
inactivated during purification, can be reactivated by addition of a thiol
-
Cloned/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
expressed in Saos2, U2OS, and A-549 cells
-
the open reading frame of the guanidinoacetate N-methyltransferase gene (NM_000156) from a fibroblast cell line is transfected into primary fibroblasts from a guanidinoacetate N-methyltransferase-deficient patient (Trp20Ser) or transient transected in HeLa cells.
Q14353
expressed in Saos2, U2OS, and A-549 cells
-
in Escherichia coli
-
recombinant enzyme truncated at amino acid 37 from N-terminus
-
EXPRESSION
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
GAMT mRNA expression is relatively low until 34 days gestation, in the fetal liver GAMT mRNA and protein expression are also relatively low until 34-37 days gestation, between mid-gestation and term neither GAMT mRNA nor protein can be detected in the placenta
-
no transcript of GAMT is detected from fertilized egg to blastula stage
Q3S316
GAMT induction in response to DNA damage is dependent upon p53, GAMT also shows p53-dependent induction in response to exogenously expressed p53 and genotoxic stress, metabolic stress induces GAMT expression to regulate creatine levels in a p53-dependent manner
-
high expression in tumor cells
-
both RNA and protein levels of GAMT are increased in a p53-dependent manner after various inducers of genotoxic stress (etoposide, H2O2, and gamma-irradiation), glucose deprivation induces GAMT in a p53-dependent manner, GAMT mRNA and protein are increased in several tissues of glucose-deprived p53 wild-type mice while remaining unchanged in the same tissues of p53 null mice
-
GAMT induction in response to DNA damage is dependent upon p53, GAMT also shows p53-dependent induction in response to exogenously expressed p53 and genotoxic stress, metabolic stress induces GAMT expression to regulate creatine levels in a p53-dependent manner
-
ENGINEERING
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
D129A
-
active enzyme
D129N
-
active enzyme
D134A
-
inactive
D134E
-
lower activity than wild type enzyme
D134N
-
much lower activity than wild type enzyme
D92N
-
lower activity than wild type enzyme
E45D
P10868
decrease in kcat-value, increase in Km-value of S-adenosyl-L-methionine
E45Q
P10868
decrease in kcat-value, increase in Km-value of S-adenosyl-L-methionine
E45S
P10868
no residual activity
E89Q
-
lower activity than wild type enzyme
G67A
-
inactive enzyme
G69A
-
inactive enzyme
T135A
-
lower activity than wild type enzyme
W143F
-
lower activity than wild type enzyme
W143L
-
lower activity than wild type enzyme
Y133F
-
lower activity than wild type enzyme
Y133V
-
lower activity than wild type enzyme
Y136F
-
higher turnover than wild type enzyme
Y136F
-
retains considerable activity, structural changes compared to wild-type
Y136V
-
lower activity than wild type enzyme
Y136V
-
loss of activity, structural changes compared to wild-type
Y221F
P10868
decrease in kcat-value
L197P
-
the sequencing of the guanidinoacetate N-methyltransferase gene reveals a homozygous missense mutation on exon 6, resulting in the substitution of leucine in position 197 with proline. The 13-year old girl has mental retardation, as main symptom, associated with a typical pattern of biochemical and neurochemical alterations.
additional information
-
mutation analysis of the guanidinoacetate methyltransferase gene is performed, the patient is found to be compound heterozygous for a known mitation in exon 2, c.327G>A, and for a novel mutation in exon 1, c170C>A
additional information
-
finding of a novel homozygous missense mutation in exon 5, p.Leu166Pro, c.497T>C
APPLICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
analysis
-
nonradioactive method for measuring enzyme activity in lymphoblasts by using HPLC with UV detector
medicine
-
guanidinoacetate methyltransferase deficiency is a rare autosomal recessive inborn error of creatine synthesis leading to accumulation of guanidinoacetate and lack of creatine in all tissues, particularly in the brain and muscle
medicine
-
guanidinoacetate methyltransferase deficient patients show intellectual disability, epilepsy and sigificant movement disorder
medicine
-
GAMT is a key enzyme in the biosynthesis of creatine, deficiency leads to severe clinical symptoms, including mental retardation, muscle hypotonia, extrapyramidal movement abnormalities and epileptic seizures
medicine
-
since creatine plays an important role in the buffering and transfer of high-energy phosphate bonds in the heart, it is hypothesized that lack of creatine would be detrimental for resting cardiac performance during ageing
medicine
-
GAMT deficiency in mouse is associated with increased neonatal mortality, muscular hypotonia, decreased male fertility and a non-leptin-mediated life-long reduction in body weight due to reduced body fat mass