25-HYDROXYVITAMIN D3-1-ALPHA-HYDROXYLASE AND DNA ENCODING THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a polypeptide useful for e.g. preventing, diagnosing and treating adult diseases such as osteoporosis caused by active vitamin D3 level drop and having the activity of the subject enzyme catalyzing the final stage of vitamin D3 activation, and to obtain a gene encoding the above polypeptide. SOLUTION: This polypeptide has an amino acid sequence or the like of the formula, having 25-hydroxyvitamin D3 -1α-hydroxylase activity; and the other objective DNA encodes this polypeptide. The polypeptide of the present invention can be recombinantly produced from the DNA of the other present invention found in a cDNA library made from a mRNA prepared from the tissue of rats bred with a vitamin D3 -lacking feed (e.g. kidney). An active vitamin D3 can be formed by making the polypeptide of the present invention and 25-hydroxyvitamin D3 exist in an aqueous medium.