Effects of L-ascorbic acid on lysyl oxidase in the formation of collagen cross-links.
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, the concentration of pyridinoline was not affected. These findings indicated that AsA was involved in the initial enzymatic reaction in pyridinoline synthesis. We purified lysyl oxidase to confirm its association of AsA. AsA inhibited the enzyme activity. Erythorbic acid and 3,4-dihydroxybenzoate suppressed the enzyme activity as well as AsA did. The inhibition by AsA of the lysyl oxidase activity arose from characteristics of AsA structure. AsA might be important in the regulation of the oxidative reaction of lysine.
Kuroyanagi
Miwa
M
Department of Nutrition and Food Science, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan.
Shimamura
Eriko
E
Kim
Mihyan
M
Arakawa
Nobuhiko
N
Fujiwara
Yoko
Y
Otsuka
Megumi
M
D000596:Amino Acids / Q000096:biosynthesis; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001013:Aorta, Thoracic / Q000187:drug effects / Q000201:enzymology; D001205:Ascorbic Acid / Q000494:pharmacology*; D002356:Cartilage / Q000737:chemistry; D002417:Cattle; D003094:Collagen / Q000737:chemistry*; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D010084:Oxidation-Reduction; D008249:Protein-Lysine 6-Oxidase / Q000737:chemistry / Q000378:metabolism*
D000596:Amino Acids; D000975:Antioxidants; D003432:Cross-Linking Reagents; C015484:pyridinoline; D003094:Collagen; D008249:Protein-Lysine 6-Oxidase; D001205:Ascorbic Acid