Lactoflavin und d-Aminosäureoxydase in der Leber tumorkranker Ratten

Publisher Website
Google Scholar
Abstract
D-Amino acid oxidase consists of a specific protein and a prosthetic group, alloxazin adenine dinucleotide. The coenzyme thus contains lactoflavin. Fresh livers from 6-22 normal rats and rats with Walker tumors are ground with sand and extracted with 8-10 vols. 80% aqueous acetone for 1 day in the dark at room temp. The mixture is centrifugalized, and the residue extracted twice more with 60% acetone. The acetone extracts are combined and concd. to 300 cc. in vacuo. The soln. is extracted with petroleum ether, which is washed twice with H2O. The alkalinity of the combined aqueous phases is adjusted to N/2 with NaOH, and the soln. in a shallow dish is irradiated for 2 hrs. at 15[degree] with a 500 W lamp at a distance of 20-25 cm. The soln. is acidified with acetic acid and the lumiflavin extracted with CHCl3. The conc. of lumiflavin is detd. in the step photometer with filter S 47 (E for 10 [gamma] lumiflavin per cc. = 0.430; 10 [gamma] lumiflavin = 15 [gamma] lactoflavin). The livers of the normal rats contain 12.4 [gamma] lactoflavin per g., and the livers of the tumor-bearing rats, 11.1 [gamma] per g. This difference is not considered to be significant. The differences in the d-amino acid oxidase activity of liver extracts of normal and tumor-bearing rats are not due to the difference in lactoflavin content. The apoenzyme of the d-amino acid oxidase in the liver extracts of the rats is almost completely (97%) bound to the coenzyme.

This publication has 2 references indexed in Scilit: