The activation by copper of chick aortic lysyl oxidase

Abstract

An in vitro method is described which was designed to study the activation by copper of lysyl oxidase in aortas from 10 day copper deficient chicks. The optimum conditions for the activation by copper of lysyl oxidase were 12 hr incubation of copper deficient chicks aortas at 37* in Waymouths medium supplemented with 5 ug/cu per ml The activation response was inhibited by cycloheximide and partially inhibited by actinomycin D. L-[4,5-3H] lysine and 64Cu added to the growth media became tightly bound to a protein extracted from the aortas by buffered 6M urea followed by passage through collagen derivatized Sepharose 4B affinity columns. The protein had a molecular weight of 60-65,000 and possibly was lysyl oxidase. The incorporation into the protein of L-[4,5-3H] lysine and 64Cu was inhibited by cycloheximide present in the growth medium but not affected by actinomycin D.