The spectral and catalytic properties of the copper cofactor in highly purified bovine aortic lysyl oxidase have been examined. As isolated, various preparations of purified lysyl oxidase are associated with 5-9 loosely bound copper atoms per molecule of enzyme which are removed by dialysis against EDTA. The enzyme also contains 0.99 +/- 0.10 g atom of tightly bound copper per 32-kDa monomer wh...

The catalysis of amine oxidation by lysyl oxidase has been probed to assess for the likely order of substrate binding and product release and to discriminate between mechanistic alternatives previously proposed for other copper-dependent amine oxidases using molecular oxygen as a substrate. Lineweaver-Burk plots revealed a pattern of parallel lines when the oxidation of n-butylamine was followe...

The structural specificity of amine oxidation by lysyl oxidase was investigated using kinetic and NMR spectroscopic analyses. Substrate efficiency increased with increasing molecular distance from the alpha-carbon of the aromatic moiety substituted on the aliphatic chains of a series of primary amines. The p-hydroxyl substituent of p-hydroxybenzylamine significantly increased kcat over that of ...

To clarify the role of L-ascorbic acid (AsA) in the formation of pyridinoline, we examined the effects of AsA in vitro using soluble collagen and partially purified lysyl oxidase from bovine aorta. The concentration of dehydrodihydroxylysinonorleucine decreased when AsA was added in the early stage of pyridinoline formation. However, when AsA was added in a later stage of pyridinoline formation...

Lysyl oxidase initiates the enzymatic stage of collagen and elastin cross-linking. Among five isoforms comprising the lysyl oxidase family, LOX is the better studied. LOX is associated to an antitumor activity in ras-transformed fibroblasts, and its expression is down-regulated in many carcinomas. The aim of this work was to shed light on LOX functions within the epidermis by studying its expre...

This study assessed the responses of lysyl oxidase, the enzyme that initiates covalent crosslinking in elastic and collagen, by studying the aortic tissue of rabbits after arteriosclerosis had been induced by diet. Rabbits in the experimental group were fed an atherogenic diet of rabbit chow supplemented with 8% peanut oil and 2% cholesterol for varying periods of time, while the control group ...

Aortic tissue from chicks raised 8 to 11 days on diets lacking copper contains diminished levels of the enzyme lysyl oxidase, a copper metalloenzyme. By incubating the deficient aortic tissue in fully oxygenated Waymouth growth medium (MB 751/2) supplemented with 3 to 5 pg/ml of CuSO4, it was possible to restore lysyl oxidase activity to the aorta. Enzyme activation required copper supplements ...

The use of recombinant human tropoelastin (rTE) and selected variants thereof as substrates for the assay of lysyl oxidase activity in vitro was explored. The possibility was also assessed that an insoluble elastin-like product could be generated from this elastin precursor in the absence of other macromolecules found associated with elastin in vivo. rTE was more efficiently oxidized by lysyl o...