Cloned (Comment) | Organism |
---|---|
expression of wild-type and mutant enzymes in HEK-293 cells | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
H205A | site-directed mutagenesis of the catalytic site residue, the mutant shows complete loss of epimerase activity | Homo sapiens |
H450A | site-directed mutagenesis of the catalytic site residue, the mutant shows complete loss of epimerase activity | Homo sapiens |
N183S | site-directed mutagenesis of an N-glycosylation site in DS-epi1 altering reaction kinetics | Homo sapiens |
N336S | site-directed mutagenesis of an N-glycosylation site in DS-epi1 altering reaction kinetics and reducing the activity 13fold | Homo sapiens |
N642S | site-directed mutagenesis of an N-glycosylation site in DS-epi1 altering reaction kinetics | Homo sapiens |
N648S | site-directed mutagenesis of an N-glycosylation site in DS-epi1 altering reaction kinetics and reducing the activity 43fold | Homo sapiens |
Y261A | site-directed mutagenesis of the catalytic site residue, the mutant shows complete loss of epimerase activity | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0049 | - |
D-glucuronate | pH 5.5, 37°C, recombinant mutant N648S | Homo sapiens | |
0.014 | - |
D-glucuronate | pH 5.5, 37°C, recombinant mutant N336S | Homo sapiens | |
0.016 | - |
D-glucuronate | pH 5.5, 37°C, recombinant mutant N183S | Homo sapiens | |
0.016 | - |
D-glucuronate | pH 5.5, 37°C, recombinant mutant N642S | Homo sapiens | |
0.024 | - |
D-glucuronate | ph 5.5, 37°C, recombinant wild-type enzyme | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | Q9UL01 | - |
- |
Posttranslational Modification | Comment | Organism |
---|---|---|
glycoprotein | proper N-glycosylation of DS-epimerase 1 is required for enzyme activity | Homo sapiens |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
Chondroitin D-glucuronate = dermatan L-iduronate | His-450 functions as a general base abstracting the C5 proton from glucuronic acid. Subsequent cleavage of the glycosidic linkage by Tyr-261 generates a 4,5-unsaturated hexuronic intermediate, which is protonated at the C5 carbon by His-205 from the side of the sugar plane opposite to the side of previous proton abstraction. Concomitant recreation of the glycosidic linkage ends the reaction, generating iduronic acid, proposed molecular mechanism of epimerization, overview | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-glucuronate | - |
Homo sapiens | L-iduronate | - |
? | |
additional information | identification of the catalytic site, and of three putative catalytic residues in DS-epimerase 1, His205, Tyr261, and His450, by tertiary structure modeling and amino acid conservation to heparinase II | Homo sapiens | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
DS-epimerase 1 | - |
Homo sapiens |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Homo sapiens |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5.5 | - |
assay at | Homo sapiens |