Possible Interaction: Copper and Methionine

“Taken together, these observations indicate that early copper accumulation alters methionine metabolism with a pattern distinct from that described previously for other liver diseases.”

“ Copper ions as well as added hydrogen peroxide are found to oxidize the methionine residue, but notably, this oxidative modification occurs only in the aggregated HTT but not in the soluble state.”

“The conversion of these methionine residues to cysteine, by site-directed mutagenesis, strongly suggests that they coordinate to copper during the process of metal transport.”

“There was a significant … between C and M for Mo levels (r = 0.…; p = 1.9%) and Cu levels (r = 0.47; p = 0.35%), between Cu C levels and GA (r = 0.54; … = 0.6%) and between Se, C levels and BW (r = 0.66; p = 1.9%).”

“HHcy induced by methionine feeding significantly increased oxidative stress, as measured by thiobarbituric-reactive substances in livers (P < .05) and genetic expression of Cu ,Zn-superoxide dismutase, in methionine-fed animals compared with controls (P < .05).”

“Copper alone shows a modest inhibitory action, which is about seven times lower than that of Trolox … prevents lipid peroxidation induced by the well-known Fe 2+ /ascorbate system (IC 50 =450 w M ) and the inhibitory effect is … by the presence of copper ions (IC 50 =… w M).”

“However, the combined results showed an exponential increase in 10−5 M Ach‐induced vasodilation as liver copper concentration increases from 0 μg Cu/g dry wt.”

“Studies were conducted to determine if the deleterious affects on chick growth of the primary antagonism between methionine and copper involves the homocysteine moiety or labile methyl group of methionine.”

“The primary antagonism between methionine and copper involves the homocysteine moiety, not the labile methyl groups.”

“This may explain why levels used of methionine and total sulfur-containing amino acids appear to be higher under field conditions (with pharmacological levels of copper ) than in laboratory conditions (without pharmacological levels of copper).”

“The addition of both methionine sources significantly improved body weight, feed consumption, and feed efficiency at all levels of copper supplementation.”

“Excess copper prevented the increase in plasma methionine.”