This experiment was designed to investigate the effects of different levels copper–methionine chelates and alfalfa powder on egg yolk cholesterol content, quality, performance in laying hens. In this experiment, a total 100 hens (Nick Chick strain, from 109 117 weeks age) were arranged into five experimental treatments, consisting 2 dietary copper chelate (2x2) factorial completely randomized d...

the objective of this study was to evaluate the effects of supplementation of different level protein diets with rumen protected methionine and lysine on performance and ruminal parameters in holstein dairy cows when in their early lactation. twenty one dairy cows in their early lactations were assigned to three treatments in a randomized block design experiment of a 35-d duration period. diets...

One of the serious problems complicating the study of transport of a solute is the occurrence of metabolic changes unnecessary to transport. Particularly when observations are prolonged, or concern a whole animal, or a tissue with extensive enzymatic potentialities, the possibility of irrelevant metabolic changes is very great. To avoid this difficulty as well as to explore the character of the...

After intravenous injection of S-adenosyl-L-homocysteine3H (homocysteine-labeled) into rats, less than 15% of the radioisotope was incorporated into protein methionine or excreted in the urine as oc-ketobutyrate. The remaining radioisotope was found associated with an unknown keto acid excreted in the urine. Intravenous injection of Sadenosyl-L-homocysteine-35S or S-adenosyl-3H-L-homocysteine (...

Two separate studies were conducted using a continuous culture fermenter system to determine effects of supplementing D,L-methionine and various methionine derivatives on degradation of methionine by ruminal bacteria. A basal diet containing 20% alfalfa hay, 20% corn silage and 60% grain mix (DM basis) was provided at a rate of 75 g DM/d per fermenter and served as an unsupplemented control in ...

An enzyme catalyzing the synthesis of L-cystathionine from the succinyl ester of L-homoserine and L-cysteine was isolated from a Salmonella mutant blocked in another step of methionine synthesis, and derepressed for cystathionine y-synthetase formation. The approximate molecular weight of the enzyme was 155,000 and it was unchanged after removal of tightly bound pyridoxal phosphate. In the abse...

The objectives of this study were to investigate the immune responses of broiler chickens fed diets supplemented with different level of chromium methionine (CrMet) in heat stress (HS) condition. Two hundred and eighty eight male broiler chickens (Ross 308) were allocated to four treatment groups (supplementation with 0, 200, 400 or 800 ppb Cr in the form of CrMet) in a completely randomized de...

Methionine sulfoxide reductase A (MsrA) catalyzes the reduction of methionine sulfoxide to methionine and is specific for the S epimer of methionine sulfoxide. The enzyme participates in defense against oxidative stresses by reducing methionine sulfoxide residues in proteins back to methionine. Because oxidation of methionine residues is reversible, this covalent modification could also functio...

The reduction of ferricytochrome c and ferricytochrome c carboxymethylated at the haem-linked methionine (residue 80) by Cr(2+) ions was studied by stopped-flow techniques. At pH6.2 the kinetics of reduction of ferricytochrome c are simple and correspond to a second-order rate constant of 1.21x10(3)m(-1).s(-1). Under identical conditions the kinetics of reduction of the carboxymethyl derivative...

An enzyme catalyzing the synthesis of L-cystathionine from the succinyl ester of L-homoserine and L-cysteine was isolated from a Salmonella mutant blocked in another step of methionine synthesis, and derepressed for cystathionine y-synthetase formation. The approximate molecular weight of the enzyme was 155,000 and it was unchanged after removal of tightly bound pyridoxal phosphate. In the abse...