Tags: Protein.
25-Hydroxyvitamin D3 1-alpha-hydroxylase (VD3 1A hydroxylase) also known as cytochrome p450 27B1 (CYP27B1) is a cytochrome P450 enzyme that in humans is encoded by the CYP27B1 gene.VD3 1A hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues including skin (keratinocytes) immune cells and bone (osteoblasts).