Cloning and expression of the oxalyl-CoA decarboxylase gene from the bacterium, Oxalobacter formigenes: prospects for gene therapy to control Ca-oxalate kidney stone formation.

Evidence suggests that the formation of calcium-oxalate stones in the urine is dependent on the saturation levels of both calcium and oxalate; thus, management of one or both of these ions in individuals susceptible to urolithiasis appears important. Since there are no known naturally occurring enzymes in vertebrates capable of degrading oxalate, we have initiated a study to insert a plant-derived oxalate degrading enzyme gene into human cells as a means of lowering plasma and urinary oxalate concentrations. We present here the cloning of the oxalyl-CoA decarboxylase gene from the bacterium Oxalobacter formigenes and its subsequent expression in a foreign environment. These results provide the basis for eventual transfer of an oxalate decarboxylase gene into mammalian cells.