TY - JOUR AU - Kispál, Gyula AU - Cseko, J AU - Alkonyi, István AU - Sándor, Attila TI - Isolation and characterization of carnitine acetyltransferase from S. cerevisiae. JF - BIOCHIMICA ET BIOPHYSICA ACTA J2 - BIOCHIM BIOPHYS ACTA VL - 1085 PY - 1991 IS - 2 SP - 217 EP - 222 PG - 6 SN - 0006-3002 DO - 10.1016/0005-2760(91)90097-2 UR - https://m2.mtmt.hu/api/publication/1426933 ID - 1426933 N1 - Export Date: 27 January 2024; CODEN: BBLLA AB - Carnitine acetyltransferase was isolated from yeast Saccharomyces cerevisiae with an apparent molecular weight of 400,000. The enzyme contains identical subunits of 65,000 Da. The Km values of the isolated enzyme for acetyl-CoA and for carnitine were 17.7 microM and 180 microM, respectively. Carnitine acetyltransferase is an inducible enzyme, a 15-fold increase in the enzyme activity was found when the cells were grown on glycerol instead of glucose. Carnitine acetyltransferase, similarly to citrate synthase, has a double localization (approx. 80% of the enzyme is mitochondrial), while acetyl-CoA synthetase was found only in the cytosol. In the mitochondria carnitine acetyltransferase is located in the matrix space. The incorporation of 14C into CO2 and in lipids showed a similar ratio, 2.9 and 2.6, when the substrate was [1-14C]acetate and [1-14C]acetylcarnitine, respectively. Based on these results carnitine acetyltransferase can be considered as an enzyme necessary for acetate metabolism by transporting the activated acetyl group from the cytosol into the mitochondrial matrix. LA - English DB - MTMT ER - TY - JOUR AU - Sümegi, Balázs AU - Porpáczy, Zoltán AU - Alkonyi, István TI - Kinetic advantage of the interaction between the fatty acid β-oxidation enzymes and the complexes of the respiratory chain JF - BIOCHIMICA ET BIOPHYSICA ACTA J2 - BIOCHIM BIOPHYS ACTA VL - 1081 PY - 1991 IS - 2 SP - 121 EP - 128 PG - 8 SN - 0006-3002 DO - 10.1016/0005-2760(91)90016-B UR - https://m2.mtmt.hu/api/publication/1060971 ID - 1060971 N1 - Export Date: 27 January 2024; CODEN: BBLLA LA - English DB - MTMT ER - TY - JOUR AU - Alkonyi, István AU - Cseko, J AU - Sándor, Attila TI - Role of the liver in carnitine metabolism: the mechanism of development of carnitine-deficient status in guinea-pigs. JF - JOURNAL OF CLINICAL CHEMISTRY AND CLINICAL BIOCHEMISTRY J2 - J CLIN CHEM CLIN BIOCHEM VL - 28 PY - 1990 IS - 5 SP - 319 EP - 321 PG - 3 SN - 0340-076X UR - https://m2.mtmt.hu/api/publication/1426937 ID - 1426937 AB - It was shown that carnitine deficiency and an impairment of the conversion of butyrobetaine into carnitine develops not only in ascorbic acid-deficient guinea-pigs but also in partially starved animals. We propose that the same mechanism, an absolute or relative ascorbic acid deficiency, is operating in both nutritional states. An increased urinary excretion greatly contributes to the development of carnitine deficiency in guinea-pigs, both in ascorbic acid deficiency and starvation. With respect to the greatly increased excretion, guinea-pig carnitine deficiency resembles the human disorder and may serve as model for it. LA - English DB - MTMT ER - TY - JOUR AU - Sándor, Attila AU - Cseko, J AU - Kispál, Gyula AU - Alkonyi, István TI - Surplus acylcarnitines in the plasma of starved rats derive from the liver. JF - JOURNAL OF BIOLOGICAL CHEMISTRY J2 - J BIOL CHEM VL - 265 PY - 1990 IS - 36 SP - 22313 EP - 22316 PG - 4 SN - 0021-9258 UR - https://m2.mtmt.hu/api/publication/1426936 ID - 1426936 N1 - Export Date: 27 January 2024; CODEN: JBCHA AB - The method used here to assess the contribution of liver to plasma acylcarnitine is based on the idea that in rat, shortly after administration of [3H]butyrobetaine the [3H]carnitine appearing in the plasma derives from the liver and so does the acyl moiety of [acyl-3H] carnitine. In the perchloric acid extracts of plasma and liver, the ester fraction of total carnitine was determined by enzymatic analysis and that of [3H]carnitines was determined by high performance liquid chromatography. The ester fraction of total carnitine in the plasma of fed rats was 32.6% while that of [3H]carnitines was 67.9%, 1 h following injection of [3H]butyrobetaine. For 48 h starved rats the equivalent values were 54.2 and 84.0%, respectively. 24 h after the administration of [3H]butyrobetaine, the ester content became the same in the total and [3H]carnitines. That the newly synthesized carnitine was more acylated (67.9 versus 32.6%, fed) indicates that liver exports acyl groups with carnitine as carrier. The observation that the ester fraction in the newly synthesized plasma carnitine increased with fasting (84.0 versus 67.9%) indicates that the surplus plasma acylcarnitine in fasting ketosis derives from the liver. Perfused livers, however, released carnitine with the same ester content (60-61%) whether they were from fed or fasted animals. Probably, the increased plasma [acylcarnitine] in fasting develops not by an increased ester output from the liver but by an altered handling in extrahepatic tissues. LA - English DB - MTMT ER - TY - JOUR AU - Sándor, Attila AU - Cseko, J AU - Alkonyi, István TI - Use of anion-exchange resin in F- form in sample processing for determination of carnitine. JF - JOURNAL OF CHROMATOGRAPHY B J2 - J CHROMATOGR B VL - 497 PY - 1989 SP - 250 EP - 257 PG - 8 SN - 1570-0232 DO - 10.1016/0378-4347(89)80025-8 UR - https://m2.mtmt.hu/api/publication/1426939 ID - 1426939 LA - English DB - MTMT ER - TY - JOUR AU - Kispál, Gyula AU - Melegh, Béla AU - Alkonyi, István AU - Sándor, Attila TI - ENHANCED UPTAKE OF CARNITINE BY PERFUSED-RAT-LIVER FOLLOWING STARVATION JF - BIOCHIMICA ET BIOPHYSICA ACTA J2 - BIOCHIM BIOPHYS ACTA VL - 896 PY - 1987 IS - 1 SP - 96 EP - 102 PG - 7 SN - 0006-3002 DO - 10.1016/0005-2736(87)90360-9 UR - https://m2.mtmt.hu/api/publication/1425640 ID - 1425640 N1 - Export Date: 27 January 2024; CODEN: BBBMB LA - English DB - MTMT ER - TY - JOUR AU - Sándor, Attila AU - Kispál, Gyula AU - Melegh, Béla AU - Alkonyi, István TI - ESTER COMPOSITION OF CARNITINE IN THE PERFUSATE OF LIVER AND IN THE PLASMA OF DONOR RATS JF - EUROPEAN JOURNAL OF BIOCHEMISTRY J2 - EUR J BIOCHEM VL - 170 PY - 1987 IS - 1-2 SP - 443 EP - 445 PG - 3 SN - 0014-2956 DO - 10.1111/j.1432-1033.1987.tb13719.x UR - https://m2.mtmt.hu/api/publication/1425634 ID - 1425634 N1 - Export Date: 27 January 2024 LA - English DB - MTMT ER - TY - JOUR AU - Porpáczy, Zoltán AU - Sümegi, Balázs AU - Alkonyi, István TI - Interaction between NAD-dependent isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase complex, and NADH:ubiquinone oxidoreductase JF - JOURNAL OF BIOLOGICAL CHEMISTRY J2 - J BIOL CHEM VL - 262 PY - 1987 IS - 20 SP - 9509 EP - 9514 PG - 6 SN - 0021-9258 UR - https://m2.mtmt.hu/api/publication/1060978 ID - 1060978 N1 - Export Date: 27 January 2024 LA - English DB - MTMT ER - TY - JOUR AU - Kispál, Gyula AU - Sümegi, Balázs AU - Alkonyi, István TI - ISOLATION AND CHARACTERIZATION OF 3-HYDROXYACYL COENZYME-A DEHYDROGENASE-BINDING PROTEIN FROM PIG-HEART INNER MITOCHONDRIAL-MEMBRANE JF - JOURNAL OF BIOLOGICAL CHEMISTRY J2 - J BIOL CHEM VL - 261 PY - 1986 IS - 30 SP - 14209 EP - 14213 PG - 5 SN - 0021-9258 UR - https://m2.mtmt.hu/api/publication/1060980 ID - 1060980 N1 - Export Date: 27 January 2024; CODEN: JBCHA LA - English DB - MTMT ER - TY - JOUR AU - Sándor, Attila AU - Kispál, Gyula AU - Melegh, Béla AU - Alkonyi, István TI - RELEASE OF CARNITINE FROM THE PERFUSED RAT-LIVER JF - BIOCHIMICA ET BIOPHYSICA ACTA J2 - BIOCHIM BIOPHYS ACTA VL - 835 PY - 1985 IS - 1 SP - 83 EP - 91 PG - 9 SN - 0006-3002 DO - 10.1016/0005-2760(85)90033-5 UR - https://m2.mtmt.hu/api/publication/1425643 ID - 1425643 N1 - Export Date: 27 January 2024; CODEN: BBLLA LA - English DB - MTMT ER -