Reference

L-Malic acid

L-Malic acid. Krcmar, Stanislav; Svozil, Karol; Homolova, Katerina (Czech. ). Czech. CS 171990 15 Mar 1978,2 pp. (Czech). (Czechoslovakia). CODEN: CZXXA9. CLASS: IC: C07C059-12. APPLICATION: CS 74-2429 4 Apr 1974. DOCUMENT TYPE: Patent CA Section: 16 (Fermentations) Hydration of fumarate [110-17-8] in a 0.5 M soln. of pH 6.5-7.2 was catalyzed by fumarate hydratase [9032-88-6] present in intact cells or homogenates of Candida utilis or C. lipolytica cultivated in media contg. alkanes and EtOH as the source of C. Up to 90% fumarate was converted to L-malate [97-67-6] after 120 min at 35°.

Rate equations and kinetics of uptake of a-aminoisobutyric acid and g-aminobutyric acid by mouse cerebrum slices incubated in media containing L(+)-lactate or a mixture of succinate, L-malate, and pyruvate as the energy source

Rate equations and kinetics of uptake of a-aminoisobutyric acid and g-aminobutyric acid by mouse cerebrum slices incubated in media containing L(+)-lactate or a mixture of succinate, L-malate, and pyruvate as the energy source. Cohen, Stephen R. (Dep. Neurochem., New York State Off. Ment. Retard. Dev. Disabil., Staten Island, NY 10314, USA). J. Neurochem., 44(2), 455-64 (English) 1985. CODEN: JONRA9. ISSN: 0022-3042. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Influx of a-aminoisobutyric acid (AIB) [62-57-7] and GABA [56-12-2] by mouse cerebrum slices incubated with L-lactate [79-33-4] or a mixt. of succinate [110-15-6], L-malate [97-67-6], and pyruvate [127-17-3] (SMP) as the energy source followed the phenomenol. rate equation for influx from pyruvate and glucose media: v = Vmax/(1 + Kt/S) + kuS, where v is rate and S is concn. of amino acid. There were 2 kinetically distinct, parallel components for concentrative uptake, 1 saturable, and 1 unsaturable. Rates were less with lactate than with pyruvate and still less with SMP (only GABA was studied), disproving the hypotheses that lower rates with pyruvate compared to glucose are due to an abnormal redox state in the tissue or to a Krebs cycle unbalanced by input at only 1 point. The carriers for AIB and GABA were qual. different. In lactate medium the capacity for each AIB carrier was unchanged, but its affinity was reduced to 66%. In lactate and SMP media the capacity of the saturable GABA carrier was diminished although its affinity was increased. Rates from these media with added glucose or a glucose analog confirm that amino acid and glucose fluxes are not coupled.