Literature summary for 3.2.1.23 extracted from

Kim, Y.; Yeom, S.; Oh, D.
Reduction of galactose inhibition via the mutation of beta-galactosidase from Caldicellulosiruptor saccharolyticus for lactose hydrolysis (2011), Biotechnol. Lett., 33, 353-358 .

Search for more literature for 3.2.1.23

Cloned(Commentary)

Cloned (Comment)	Organism
expressed in Escherichia coli ER2566	Caldicellulosiruptor saccharolyticus

Protein Variants

Protein Variants	Comment	Organism
E359A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The E359A mutant exhibits no activity	Caldicellulosiruptor saccharolyticus
F349A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The F349A, R111A, and W187A mutant enzyme in the presence of galactose shows remaining activity of 65%	Caldicellulosiruptor saccharolyticus
F349S	mutant exhibits the highest activity in the presence of galactose relative to the activity measured in the absence of galactose among the tested mutant enzymes at position 349. The Ki-value for galactose of the F349S mutant (160 mM), which is 13fold that of the wild-type enzyme, is the highest among the reported values of beta-galactosidase. The wild-type enzyme hydrolyzes 62% of 100 g lactose/l with the addition of 30 g galactose/l, whereas the F349S mutant hydrolyzes more than 99%	Caldicellulosiruptor saccharolyticus
H362A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The H362A mutant in the presence of galactose exhibits remaining activity below 30%	Caldicellulosiruptor saccharolyticus
I44A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The I44A mutant in the presence of galactose exhibits remaining activity below 30%	Caldicellulosiruptor saccharolyticus
N149A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The N149A mutant in the presence of galactose exhibits remaining activity below 30%	Caldicellulosiruptor saccharolyticus
R111A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The F349A, R111A, and W187A mutant enzyme in the presence of galactose shows remaining activity of 46%	Caldicellulosiruptor saccharolyticus
S41A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The S41A mutant in the presence of galactose exhibits remaining activity below 30%	Caldicellulosiruptor saccharolyticus
W187A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The F349A, R111A, and W187A mutant enzyme in the presence of galactose shows remaining activity of 44%	Caldicellulosiruptor saccharolyticus
W319A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The W319A mutant in the presence of galactose exhibits remaining activity below 30%	Caldicellulosiruptor saccharolyticus
Y281A	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The Y281A mutant exhibits no activity	Caldicellulosiruptor saccharolyticus

Inhibitors

Inhibitors	Comment	Organism	Structure
D-galactose	30 g galactose/l. The wild-type enzyme exhibits 13% remaining activity relative to the activity observed in the absence of galactose. The Y281A and E359A mutants exhibit no activity and the S41A, I44A, N149A, W319A, and H362A mutants in the presence of galactose exhibit remaining activity below 30%. The F349A, R111A, and W187A mutant enzymes in the presence of galactose show remaining activity of 65, 46, and 44%, respectively	Caldicellulosiruptor saccharolyticus

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
80000	-	-	Caldicellulosiruptor saccharolyticus

Organism

Organism	UniProt	Comment	Textmining
Caldicellulosiruptor saccharolyticus	A4XI97	-	-

Purification (Commentary)

Purification (Comment)	Organism
-	Caldicellulosiruptor saccharolyticus

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
4-nitrophenyl beta-D-galactopyranoside + H2O	-	Caldicellulosiruptor saccharolyticus	4-nitrophenol + beta-D-galactopyranose	-	?

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
80	-	assay at	Caldicellulosiruptor saccharolyticus

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism	Structure
12	-	D-galactose	pH 6.0, 80°C, wild-type enzyme	Caldicellulosiruptor saccharolyticus
70	-	D-galactose	pH 6.0, 80°C, mutant enzyme F349V	Caldicellulosiruptor saccharolyticus
147	-	D-galactose	pH 6.0, 80°C, mutant enzyme F349L	Caldicellulosiruptor saccharolyticus
156	-	D-galactose	pH 6.0, 80°C, mutant enzyme F349A	Caldicellulosiruptor saccharolyticus
160	-	D-galactose	pH 6.0, 80°C, mutant enzyme F349S	Caldicellulosiruptor saccharolyticus

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Release 2023.1 (January 2023)