1.14.15.22: vitamin D 1,25-hydroxylase

complete loss of activity

I293A

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 5.4 mmol of product per min and mol of protein, 25-hydroxyvitamin D3 hydroxylation activity at C1alpha 3.4 mmol of product per min and mol of protein

L180A

complete loss of activity

R193A

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 0.48 mmol of product per min and mol of protein, 25-hydroxyvitamin D3 hydroxylation activity at C1alpha 0.72 mmol of product per min and mol of protein

R193K

complete loss of activity

R193Q

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 0.33 mmol of product per min and mol of protein, 25-hydroxyvitamin D3 hydroxylation activity at C1alpha 0.31 mmol of product per min and mol of protein

R73A

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 30.9 mmol of product per min and mol of protein, 25-hydroxyvitamin D3 hydroxylation activity at C1alpha 20.8 mmol of product per min and mol of protein

R73A/R84A

variant is also capable of converting vitamin D2 to its active form, that is, 1alpha,25-dihydroxyvitamin D2, via 25-hydroxyvitamin D2, with its 1alpha-hydroxylation activity toward 25-hydroxyvitamin D2 being much lower than that toward 25-hydroxyvitamin D3. The substitutions enhance both 25- and 26-hydroxylation activity toward vitamin D2. After 25-hydroxylation of vitamin D2, further hydroxylation at C26 may occur frequently without the release of 25-hydroxyvitamin D2 from the substrate-binding pocket

737618

R73V/R84A

3 entries

R84A

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 75.7 mmol of product per min and mol of protein, 25-hydroxyvitamin D3 hydroxylation activity at C1alpha 34.5 mmol of product per min and mol of protein

R84F

mutation gives preference to the 1alpha-hydroxylation of 25-hydroxyvitamin D 3 over the 25-hydroxylation of 1alpha-hydroxyvitamin D 3, opposite to the wild type

737668

R89A

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 0.25 mmol of product per min and mol of protein, no 25-hydroxyvitamin D3 hydroxylation activity at C1alpha

S236A

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 4.6 mmol of product per min and mol of protein, 25-hydroxyvitamin D3 hydroxylation activity at C1alpha 3.4 mmol of product per min and mol of protein

V181A

complete loss of activity

V88A

1alpha-hydroxyvitamin D3 hydroxylation activity at C25 1.52 mmol of product per min and mol of protein, 25-hydroxyvitamin D3 hydroxylation activity at C1alpha 0.34 mmol of product per min and mol of protein