Literature summary for 6.3.2.61 extracted from

Regnard, C.; Audebert, S.; Desbruyeres, E.; Denoulet, P.; Edde, B.
Tubulin polyglutamylase partial purification and enzymatic properties (1998), Biochemistry, 37, 8395-8404 .

Search for more literature for 6.3.2.61

General Stability

General Stability	Organism
at 30°C, the loss of activity is reduced to 40% in the presence of 0.1 mg/ml microtubules, while neither bovine serum albumin nor the other substrates, ATP or glutamate, have any protecting effect	Mus musculus

Inhibitors

Inhibitors	Comment	Organism	Structure
citrate	about 90% inhibition at 10 mM	Mus musculus
KCl	5-10 mM, strong inhibitory effect on the glutamylation reaction. 80 mM, 90% inhibition; strong inhibitory effect	Mus musculus
Na2SO4	90% inhibition at 20 mM	Mus musculus
NaCl	5-10 mM, strong inhibitory effect on the glutamylation reaction. 40 mM NaCl, 50% inhibition; strong inhibitory effect	Mus musculus
Sodium acetate	100 mM, 50% onhibition	Mus musculus
Sodium citrate	90% inhibition at 10 mM	Mus musculus
Sodium sulfate	about 90% inhibition at 20 mM	Mus musculus

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.1	-	ATP	30°C, pH 8.7	Mus musculus
0.8	-	L-glutamate	30°C, pH 8.7	Mus musculus
3	-	L-glutamate	30°C, pH 6.8	Mus musculus

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Mg2+	absolutely required with an optimal concentration of 6-8 mM	Mus musculus
Mg2+	required, 8 mM used in assay conditions. The activity increases markedly with Mg2+ concentrations between 1 and 6 mM	Mus musculus

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
360000	-	-	Mus musculus
360000	-	gel filtration	Mus musculus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
n ATP + [alpha-tubulin]-L-glutamate + n L-glutamate	Mus musculus	overall reaction	[alpha-tubulin]-(gamma-(poly-alpha-L-glutamyl)-L-glutamyl)-L-glutamate + n ADP + n phosphate	-	?
n ATP + [beta-tubulin]-L-glutamate + n L-glutamate	Mus musculus	overall reaction	[beta-tubulin]-(gamma-(poly-alpha-L-glutamyl)-L-glutamyl)-L-glutamate + n ADP + n phosphate	-	?

Organism

Organism	UniProt	Comment	Textmining
Mus musculus	-	-	-

Purification (Commentary)

Purification (Comment)	Organism
-	Mus musculus
phosphocellulose column chromatography, MgCl2 and sodium citrate precipitation, sucrose gradient sedimentation, and TSK G3000 gel filtration	Mus musculus

Source Tissue

Source Tissue	Comment	Organism	Textmining
brain	-	Mus musculus	-

Storage Stability

Storage Stability	Organism
-80°C, 10% glycerol, stable for several months	Mus musculus
-80°C, in the presence of 10% (v/v) glycerol, several months, no loss of activity	Mus musculus
20°C, in 10 mM Tris (pH 8.7), 1 mM EGTA, 1 mM MgCl2, 1 mM dithiothreitol, and 0.01% TX-100 at pH 8.7, 1 h, 50% loss of activity	Mus musculus
30°C, in 10 mM Tris (pH 8.7), 1 mM EGTA, 1 mM MgCl2, 1 mM dithiothreitol, and 0.01% TX-100 at pH 8.7, 1 h, 75% loss of activity	Mus musculus

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
ATP + [alpha-tubulin]-L-glutamate + L-glutamate	the enzyme catalyzes the MgATP-dependent addition of L-glutamate onto tubulin subunits. The enzyme is active with alpha- and beta-tubulin, respectively. Microtubules are much better substrates than unpolymerized tubulin, and the reaction is very specific for glutamate, other amino acids or glutamate analogues not being substrates. Moreover, glutamyl units are added sequentially onto tubulin, leading to progressive elongation of the polyglutamyl side chains. Side chains of one to six or seven glutamyl units are obtained with microtubules, whereas much longer side chains (up to 15-20 units) are formed with unpolymerized tubulin	Mus musculus	?	-	?
ATP + [beta-tubulin]-L-glutamate + L-glutamate	the enzyme catalyzes the MgATP-dependent addition of L-glutamate onto tubulin subunits. The enzyme is active with alpha- and beta-tubulin, respectively. Microtubules are much better substrates than unpolymerized tubulin, and the reaction is very specific for glutamate, other amino acids or glutamate analogues not being substrates. Moreover, glutamyl units are added sequentially onto tubulin, leading to progressive elongation of the polyglutamyl side chains. Side chains of one to six or seven glutamyl units are obtained with microtubules, whereas much longer side chains (up to 15-20 units) are formed with unpolymerized tubulin	Mus musculus	?	-	?
additional information	microtubules are much better substrates than unpolymerized tubulin, and the reaction is very specific for L-glutamate, other amino acids (D-Glu, L-Asp, L-Gln, L-Asn, L-Ser, L-Lys, L-Leu, and L-Gly) or glutamate analogues (RGlu-Glu, çGlu-Glu, Iso-Gln, N-acetyl-Glu, norvaline, GABA, and Gla) not being substrates. Moreover, glutamyl units are added sequentially onto tubulin, leading to progressive elongation of the polyglutamyl side chains. Side chains of 1-6 or 7 glutamyl units are obtained with microtubules, whereas much longer side chains (up to 15-20 units) are formed with unpolymerized tubulin	Mus musculus	?	-	-
n ATP + [alpha-tubulin]-L-glutamate + n L-glutamate	overall reaction	Mus musculus	[alpha-tubulin]-(gamma-(poly-alpha-L-glutamyl)-L-glutamyl)-L-glutamate + n ADP + n phosphate	-	?
n ATP + [beta-tubulin]-L-glutamate + n L-glutamate	overall reaction	Mus musculus	[beta-tubulin]-(gamma-(poly-alpha-L-glutamyl)-L-glutamyl)-L-glutamate + n ADP + n phosphate	-	?

Synonyms

Synonyms	Comment	Organism
tubulin polyglutamylase	-	Mus musculus

Temperature Stability [°C]

Temperature Stability Minimum [°C]	Temperature Stability Maximum [°C]	Comment	Organism
20	-	pH 8.7, 1 h, 50% loss of activity. Not significant loss of activity within 3 h of incubation at pH 6.8	Mus musculus
30	-	pH 8.7, 1 h, 75% loss of activity. No significant loss of activity within 3 h of incubation at pH 6.8	Mus musculus

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
additional information	-	the high pH optimum observed at low glutamate concentrations is a result of the free amine of glutamate (pK = 9.7 at 25°C) being the substrate for the reaction	Mus musculus
8.3	8.9	-	Mus musculus

pH Range

pH Minimum	pH Maximum	Comment	Organism
6.8	8.9	the enzyme activity increases markedly with the pH going from 6.8 to 8.3, with a large optimum between 8.3 and 8.9, and then decreases sharply. At physiological pH, the activity is 15% of the maximal level	Mus musculus
7.5	9.2	pH 7.5: about 45% of maximal activity, pH 9.2: about 80% of maximal activity. When the glutamate concentration is raised to 6 mM, the activity is less dependent on pH, decreasing by only 40% between pH 8.7 and 6.8	Mus musculus

pH Stability

pH Stability	pH Stability Maximum	Comment	Organism
6.8	-	3 h, no significant loss of activity at 20°C and at 30°C	Mus musculus
8.7	-	1 h, 50% loss of activity at 20°C and 75% at 30°C. At 30°C, the loss is reduced to 40% in the presence of 0.1 mg/ml microtubules	Mus musculus

General Information

General Information	Comment	Organism
physiological function	the enzyme catalyzes the posttranslational formation of polyglutamyl side chains onto alpha- and beta-tubulin. The length of the polyglutamyl side chain regulates the interaction between tubulin and various microtubule-associated proteins	Mus musculus

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Release 2023.1 (January 2023)