Metabolism of methionine and methionine hydroxy analogue by porcine kidney fibroblasts.
Porcine kidney fibroblasts in culture are able to utilize the 2-hydroxy analog of methionine (MHA) as the sole methionine source, but higher concentrations of MHA than methionine are required. The optimal concentration for growth with L-methionine ranges from 0.02 to 1.0 mM, whereas that for DL-MHA is 7.5 mM. At concentrations above 1.0 mM, L-methionine exhibits a toxic effect. Supplementing 1.0 mM L-methionine with DL-MHA allows greater growth than that provided by an equimolar concentration of L-methionine alone, and no toxic effect is seen at methionine source (DL-MHA) concentrations up to 7.5 mM. Early in the growth phase of cells where DL-MHA is the sole source of methionine, a 48-h lag period is observed over that seen in cells grown in the presence of 1.0 mM L-methionine. After the lag period, the MHA-supplemented cells double at the same rate as the methionine-supplemented cells. Studies with the purified isomers of D- and L-MHA indicate that only the D-isomer is utilized by these fibroblasts.
Schreiner
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Department of Biochemistry, North Carolina State University, Raleigh 27695.
Jones
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EE
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004357:Drug Synergism; D005347:Fibroblasts / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008715:Methionine / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology / Q000633:toxicity; D014176:Protein Biosynthesis; D013237:Stereoisomerism; D013552:Swine
C008391:alpha-hydroxy-gamma-methylmercaptobutyric acid; D004247:DNA; D008715:Methionine