Literature summary for 4.4.1.20 extracted from

Niegowski, D.; Kleinschmidt, T.; Olsson, U.; Ahmad, S.; Rinaldo-Matthis, A.; Haeggstroem, J.Z.
Crystal structures of leukotriene C4 synthase in complex with product analogs: implications for the enzyme mechanism (2014), J. Biol. Chem., 289, 5199-5207.

Cloned(Commentary)

Cloned (Comment)	Organism
recombinant expression of wild-type and mutant enzymes in Pichia pastoris strain KM71H	Homo sapiens

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified enzyme in apoform or in complex with either one of three product analogues, S-hexyl-, 4-phenyl-butyl-, and 2-hydroxy-4-phenyl-butyl-glutathione, sitting drop vapor diffusion, mixing of 0.001 ml of 3.5 mg/ml protein solution containing 1 mM GSH with 0.001 ml of reservoir solution containing 1.8-2.2 M NH4SO4, 0.2 M NaCl, and 0.1 M sodium cacodylate, pH 6.1-6.8, 1-4 days, room temperature, soaking in 1 mM ligand solutions, X-ray diffraction structure determination and analysis at 2.4-3.2 A resolution	Homo sapiens

Crystallization (Comment)

Organism

purified enzyme in apoform or in complex with either one of three product analogues, S-hexyl-, 4-phenyl-butyl-, and 2-hydroxy-4-phenyl-butyl-glutathione, sitting drop vapor diffusion, mixing of 0.001 ml of 3.5 mg/ml protein solution containing 1 mM GSH with 0.001 ml of reservoir solution containing 1.8-2.2 M NH4SO4, 0.2 M NaCl, and 0.1 M sodium cacodylate, pH 6.1-6.8, 1-4 days, room temperature, soaking in 1 mM ligand solutions, X-ray diffraction structure determination and analysis at 2.4-3.2 A resolution

Homo sapiens

Protein Variants

Protein Variants	Comment	Organism
W116A	site-directed mutagenesis, altered kinetics compared to the wild-type enzyme	Homo sapiens
W116F	site-directed mutagenesis, the mutant shows a 3fold increased turnover of leukotriene A4 compared to the wild-type enzyme	Homo sapiens

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism
0.03	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant wild-type enzyme	Homo sapiens
0.04	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant mutant W116A	Homo sapiens
0.095	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant mutant W116F	Homo sapiens
0.3	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant wild-type enzyme	Homo sapiens
1.42	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant mutant W116A	Homo sapiens
2.38	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant mutant W116F	Homo sapiens

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
endoplasmic reticulum membrane	integral membrane protein in the outer leaflet of the nuclear envelope and in the endoplasmic reticulum	Homo sapiens	5789	-

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
leukotriene A4 + glutathione	Homo sapiens	-	leukotriene C4	-	?

Organism

Organism	UniProt	Comment	Textmining
Homo sapiens	Q16873	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
leukotriene A4 + glutathione	-	Homo sapiens	leukotriene C4	-	?
leukotriene A4 + glutathione	glutathione-enzyme binding structure, overview	Homo sapiens	leukotriene C4	i.e. (5S)-hydroxy-(6R)-S-glutathionyl-7,9-trans-11,14-cis-eicosatetraenoic acid	?

Synonyms

Synonyms	Comment	Organism
leukotriene C4 synthase	-	Homo sapiens
LT C4 synthase	-	Homo sapiens
LTC4S	-	Homo sapiens

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism
12	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant wild-type enzyme	Homo sapiens
16.8	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant mutant W116A	Homo sapiens
17.7	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant mutant W116F	Homo sapiens
26	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant wild-type enzyme	Homo sapiens
32	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant mutant W116A	Homo sapiens
74.3	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant mutant W116F	Homo sapiens

General Information

General Information	Comment	Organism
evolution	the enzyme belongs to the superfamily of membrane-associated proteins in eicosanoid and glutathione metabolism, which consists of six integral membrane proteins	Homo sapiens
additional information	enzyme residue Trp116 is not essential for catalysis but helps position the omega-end of leukotriene A4	Homo sapiens
physiological function	the enzyme catalyzes the conjugation reaction between the fatty acid leukotriene A4 and GSH to form the pro-inflammatory leukotriene C4, an important mediator of asthma	Homo sapiens

kcat/KM [mM/s]

kcat/KM Value [1/mMs^-1]	kcat/KM Value Maximum [1/mMs^-1]	Substrate	Comment	Organism
7	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant mutant W116F	Homo sapiens
11	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant mutant W116A	Homo sapiens
40	-	leukotriene A4	pH 7.8, temperature not specified in the publication, recombinant wild-type enzyme	Homo sapiens
730	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant mutant W116F	Homo sapiens
810	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant mutant W116A	Homo sapiens
870	-	glutathione	pH 7.8, temperature not specified in the publication, recombinant wild-type enzyme	Homo sapiens