Literature summary for 4.2.1.22 extracted from

Mendes, M.I.; Santos, A.S.; Smith, D.E.; Lino, P.R.; Colaco, H.G.; de Almeida, I.T.; Vicente, J.B.; Salomons, G.S.; Rivera, I.; Blom, H.J.; Leandro, P.
Insights into the regulatory domain of cystathionine beta-synthase characterization of six variant proteins (2014), Hum. Mutat., 35, 1195-1202 .

Search for more literature for 4.2.1.22

Activating Compound

Activating Compound	Comment	Organism	Structure
S-adenosyl-L-methionine	half-activation of wild-type at 0.0258 mM, mutant D444N 1.234 mM, mutant S500L 0.063 mM, respectively	Homo sapiens

Protein Variants

Protein Variants	Comment	Organism
D444N	about 95% of wild-type activity, increase in the basal enzymatic activity in presence of pyridoxal 5'-phosphate	Homo sapiens
K523Sfs?18	enzymatic function of the variants is not impaired, increase in the basal enzymatic activity in presence of pyridoxal 5'-phosphate	Homo sapiens
L540Q	enzymatic function of the variants is not impaired, increase in the basal enzymatic activity in presence of pyridoxal 5'-phosphate	Homo sapiens
P427L	enzymatic function of the variants is not impaired. Mutant lacks activation by S-adenosyl-L-methionine, but binds it at low level and shows an increase in the basal enzymatic activity in presence of pyridoxal 5'-phosphate	Homo sapiens
S500L	about 71% of wild-type activity. Mutant lacks activation by S-adenosyl-L-methionine, but binds it at low level and shows an increase in the basal enzymatic activity in presence of pyridoxal 5'-phosphate	Homo sapiens
V449G	enzymatic function of the variants is not impaired, increase in the basal enzymatic activity in presence of pyridoxal 5'-phosphate	Homo sapiens

Inhibitors

Inhibitors	Comment	Organism	Structure
L-homocysteine	-	Homo sapiens

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.29	-	L-homocysteine	wild-type, 37°C, pH not specified in the publication	Homo sapiens
0.31	-	L-homocysteine	mutant K523Sfs?18, 37°C, pH not specified in the publication	Homo sapiens
0.32	-	L-homocysteine	mutant S500L, 37°C, pH not specified in the publication	Homo sapiens
0.35	-	L-homocysteine	mutant V449G, 37°C, pH not specified in the publication	Homo sapiens
0.4	-	L-homocysteine	mutant D444N, 37°C, pH not specified in the publication	Homo sapiens
0.47	-	L-homocysteine	mutant L540Q, 37°C, pH not specified in the publication	Homo sapiens
0.69	-	L-homocysteine	mutant P427L, 37°C, pH not specified in the publication	Homo sapiens
1.9	-	L-serine	mutant L540Q, 37°C, pH not specified in the publication	Homo sapiens
2	-	L-serine	mutant P427L, 37°C, pH not specified in the publication	Homo sapiens
2.1	-	L-serine	mutant S500L, 37°C, pH not specified in the publication	Homo sapiens
2.7	-	L-serine	mutant V449G, 37°C, pH not specified in the publication	Homo sapiens
2.9	-	L-serine	mutant D444N, 37°C, pH not specified in the publication	Homo sapiens
3.6	-	L-serine	wild-type, 37°C, pH not specified in the publication	Homo sapiens
3.7	-	L-serine	mutant K523Sfs?18, 37°C, pH not specified in the publication	Homo sapiens

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
250000	-	dynamic light scattering	Homo sapiens

Organism

Organism	UniProt	Comment	Textmining
Homo sapiens	P35520	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
L-serine + L-homocysteine	-	Homo sapiens	L-cystathionine + H2O	-	?

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism	Structure
3.9	-	L-homocysteine	mutant K523Sfs?18, 37°C, pH not specified in the publication	Homo sapiens
7.7	-	L-homocysteine	mutant P427L, 37°C, pH not specified in the publication	Homo sapiens
12	-	L-homocysteine	mutant V449G, 37°C, pH not specified in the publication	Homo sapiens
12.8	-	L-homocysteine	mutant L540Q, 37°C, pH not specified in the publication	Homo sapiens
12.8	-	L-homocysteine	wild-type, 37°C, pH not specified in the publication	Homo sapiens
13.4	-	L-homocysteine	mutant D444N, 37°C, pH not specified in the publication	Homo sapiens
27.8	-	L-homocysteine	mutant S500L, 37°C, pH not specified in the publication	Homo sapiens

kcat/KM [mM/s]

kcat/KM Value [1/mMs^-1]	kcat/KM Value Maximum [1/mMs^-1]	Substrate	Comment	Organism	Structure
0.34	-	L-serine	wild-type, 37°C, pH not specified in the publication	Homo sapiens
0.46	-	L-serine	mutant D444N, 37°C, pH not specified in the publication	Homo sapiens
0.71	-	L-serine	mutant K523Sfs?18, 37°C, pH not specified in the publication	Homo sapiens
0.83	-	L-serine	mutant V449G, 37°C, pH not specified in the publication	Homo sapiens
1.06	-	L-serine	mutant S500L, 37°C, pH not specified in the publication	Homo sapiens
1.93	-	L-serine	mutant P427L, 37°C, pH not specified in the publication	Homo sapiens
2.8	-	L-homocysteine	mutant D444N, 37°C, pH not specified in the publication	Homo sapiens
3	-	L-homocysteine	wild-type, 37°C, pH not specified in the publication	Homo sapiens
3.61	-	L-serine	mutant L540Q, 37°C, pH not specified in the publication	Homo sapiens
4.71	-	L-homocysteine	mutant V449G, 37°C, pH not specified in the publication	Homo sapiens
4.82	-	L-homocysteine	mutant S500L, 37°C, pH not specified in the publication	Homo sapiens
5.22	-	L-homocysteine	mutant K523Sfs?18, 37°C, pH not specified in the publication	Homo sapiens
5.23	-	L-homocysteine	mutant P427L, 37°C, pH not specified in the publication	Homo sapiens
11	-	L-homocysteine	mutant L540Q, 37°C, pH not specified in the publication	Homo sapiens

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Release 2023.1 (January 2023)