Literature summary for 3.4.21.6 extracted from

Chan, C.W.; Chan, M.W.; Liu, M.; Fung, L.; Cole, E.H.; Leibowitz, J.L.; Marsden, P.A.; Clark, D.A.; Levy, G.A.
Kinetic analysis of a unique direct prothrombinase, fgl2, and identification of a serine residue critical for the prothrombinase activity (2002), J. Immunol., 168, 5170-5177.

Search for more literature for 3.4.21.6

Activating Compound

Activating Compound	Comment	Organism	Structure
Factor Va	absolutely required for activity as part of the prothrombinase complex	Mus musculus

Cloned(Commentary)

Cloned (Comment)	Organism
gene fgl2, expression of the full sized, His-tagged enzyme in Spodoptera frugiperda Sf9 cells via transfection with baculovirus, expression of truncated enzyme forms and enzyme mutants in CHO-K1 cells	Mus musculus

Protein Variants

Protein Variants	Comment	Organism
additional information	expression of several differently truncated enzymes reveal that residues 285-335 are critical for prothrombinase activity, a truncated enzyme lacking these residues is catalytically inactive	Mus musculus
S135A	site-directed mutagenesis, unaltered activity compared to the wild-type enzyme	Mus musculus
S425A	site-directed mutagenesis, unaltered activity compared to the wild-type enzyme	Mus musculus
S89A	site-directed mutagenesis, completely inactive mutant	Mus musculus

Inhibitors

Inhibitors	Comment	Organism	Structure
4-aminobenzamidine	90% inhibition of factor Xa and 2% inhibition of prothrombinase complex activity at 1 mM	Mus musculus
antithrombin III	90% inhibition of factor Xa at 0.01 mg/ml in presence of heparin and 5% inhibition of prothrombinase complex activity at 1 U/ml	Mus musculus
Aprotinin	95% inhibition of factor Xa and 2% inhibition of prothrombinase complex activity at 10 U/ml	Mus musculus
diisopropylfluorophosphate	2.5 mM: 10% inhibition of factor Xa and 95% inhibition of prothrombinase complex activity, 10 mM: 90% inhibition of factor Xa and 95% inhibition of prothrombinase complex activity	Mus musculus
PMSF	complete inhibition of factor Xa and 5% inhibition of prothrombinase complex activity at 1 mM	Mus musculus
Soybean trypsin inhibitor	complete inhibition of factor Xa and 5% inhibition of prothrombinase complex activity at 0.01 mg/ml	Mus musculus

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.0072	-	prothrombin	pH 7.4, 37°C, wild-type enzyme in presence of factor Va	Mus musculus
0.0083	-	prothrombin	pH 7.4, 37°C, wild-type enzyme	Mus musculus

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Ca2+	absolutely required for activity as part of the prothrombinase complex	Mus musculus
phosphatidyl-L-serine	best in lipid vesicles with up to 25% phosphatidyl-L-serine and at least 75% phosphocholine, absolutely required for activity as part of the prothrombinase complex	Mus musculus
phosphocholine	best in lipid vesicles with up to 25% phosphatidyl-L-serine and at least 75% phosphocholine	Mus musculus

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
65000	-	x * 65000, recombinant wild-type enzyme, SDS-PAGE	Mus musculus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
prothrombin + H2O	Mus musculus	-	thrombin + ?	-	?

Organism

Organism	UniProt	Comment	Textmining
Mus musculus	-	gene fgl2	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant His-tagged wild-type enzyme from Sf9 insect cells, to homogeneity	Mus musculus

Reaction

Reaction	Comment	Organism	Reaction ID
selective cleavage of Arg-/-Thr and then Arg-/-Ile bonds in prothrombin to form thrombin	scutelarin has similar specificity, Ser89 is critical for enzyme activity	Mus musculus	a

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
additional information	-	coagulation activity of different, recombinant enzymes forms in presence of varying mixtures of phospholipids	Mus musculus

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
D-hexahydrotyrosyl-L-alanyl-L-arginine-4-nitroanilide + H2O	synthetic chromogenic substrate	Mus musculus	D-hexahydrotyrosyl-L-alanyl-L-arginine + 4-nitroaniline	-	?
prothrombin + H2O	-	Mus musculus	thrombin + ?	-	?
prothrombin + H2O	the recombinantly expressed enzyme is inactive in Sf9 cells, activity can be restored by addition of phosphatidyl-L-serine, and further enhanced by addition of factor Va and Ca2+	Mus musculus	thrombin + ?	-	?

Subunits

Subunits	Comment	Organism
?	x * 65000, recombinant wild-type enzyme, SDS-PAGE	Mus musculus
More	factor Xa is part of the prothrombinase complex with Ca2+, phospholipids and factor Va	Mus musculus

Synonyms

Synonyms	Comment	Organism
factor Xa	-	Mus musculus
Fgl2 protein	-	Mus musculus
More	the enzyme belongs to the peptidase family S1, i.e. trypsin family	Mus musculus

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
37	-	assay at	Mus musculus

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
7	7.4	assay at	Mus musculus

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Release 2023.1 (January 2023)