Six ethionine-resistant (Etr) regulatory mutants of Saccharomycopsis lipolytica Sl/1 overproducing methionine have been isolated. Five of them are also resistant to seleno-methionine. The activity of homocysteine synthase (O-acetyl-L-hormoserine-acetate lyase, adding hydrogen sulfide) is derepressed in these mutants and is not susceptible to the methionine-mediated repression. The pool of free ...

Methionine residues in alpha/beta-type small, acid-soluble spore proteins (SASP) of Bacillus species were readily oxidized to methionine sulfoxide in vitro by t-butyl hydroperoxide (tBHP) or hydrogen peroxide (H2O2). These oxidized alpha/beta-type SASP no longer bound to DNA effectively, but DNA binding protected alpha/beta-type SASP against methionine oxidation by peroxides in vitro. Incubatio...

1. Metabolism, in broiler chicks, of DL-2-hydroxy 4-methylthiobutanoic acid (DL-HMB), DL-methionine and L-methionine was compared in vivo using 14C-labelled tracers. 2. The distribution of L-[1-14C]methionine and DL-[1-14C]HMB in the major body tissues was examined for a period of 120 min after administration. 3. The relative oxidation (14CO2 exhaled), excretion and incorporation into tissue pr...

In a previous communication from this laboratory (l), a method was described for the enzymatic resolution of Dr.,-methionine. The ready availability of the optically active enantiomorphs has made possible the application of the carbobenzoxy method to the synthesis of peptides of Land n-methionine. A search of the literature has indicated that the only methionine peptide described thus far is gl...

Supplemental methionine in a complete culture medium increased the methionine content of the protein fraction of cultured soybean (Glycine max L. Merrill) cotyledons (Thompson, Madison, Muenster 1981 Phytochemistry 20: 941-945). To explain the observed increase in protein methionine, we have measured the amounts and subunit compositions of 7S and 11S storage proteins and determined the amino ac...

We recently showed that the developing gut is a significant site of methionine transmethylation to homocysteine and transsulfuration to cysteine. We hypothesized that sulfur amino acid (SAA) deficiency would preferentially reduce mucosal growth and antioxidant function in neonatal pigs. Neonatal pigs were enterally fed a control or an SAA-free diet for 7 days, and then whole body methionine and...

The death of a control subject after an oral load of methionine for a study of the possible relationship between homocysteine and Alzheimer's disease is reported. The subject developed postload plasma concentrations of methionine far beyond those reported previously in humans given the usual oral loading dose of methionine (100 mg/kg body wt). Her preload plasma metabolite values rule out known...

Anserine and carnosine in the muscle of growing rats were measured to explore the effect of dietary methionine. Carnosine was reduced in the gastrocnemius muscle of rats fed on a methionine-free diet. After refeeding on methionine for one week, carnosine in the muscle approached to the normal level. In contrast, anserine increased in the muscle of rats fed on a methionine-free diet. Anserine al...

OBJECTIVE S-Adenosylmethionine (SAMe) is a major methyl donor in the brain and is also an antidepressant with few reported side effects; however, SAMe is relatively expensive and unstable. Brain SAMe can be increased by giving methionine to rats, raising the possibility that methionine may be an antidepressant. We aimed to study whether SAMe and methionine, when given orally to rats, could rais...

Shake cultures, in contrast to static cultures of Penicillium digitatum grown in liquid medium, were induced by methionine to produce ethylene. The induction was concentration-dependent, and 7 mM was optimum for the methionine effect. In the presence of methionine, glucose (7 mM) enhanced ethylene production but did not itself induce ethylene production. The induction process lasted several hou...