caa a22 4500 477119697 CHVBK 20180405111632.0 cr unu---uuuuu 170330e19960301xx s 000 0 eng 10.1007/BF00240035 doi (NATIONALLICENCE)springer-10.1007/BF00240035 Kinetics of myocardial phospholipase D [Elektronische Daten] [Jian Dai, Song-Yan Liu, Vincenzo Panagia] Myocardial phospholipase D (PLD) is located in different subcellular membranes, including sarcolemma (SL) and sarcoplasmic reticulum (SR). In this study, the kinetics of PLD-dependent hydrolytic and transphosphatidylation activities were examined in SL and SR fractions isolated from rat heart by measuring the formation of phosphatidic acid and phosphatidylethanol, respectively. The results showed that, compared to SR PLD, SL PLD had a higher Vmax, i.e. 373 vs. 70 nmol/mg protein/h for the hydrolytic activity and 415 vs. 60 nmol/mg protein/h for the transphosphatidylation activity. In comparison with the SR enzyme, SL PLD had a lower Km value for the hydrolytic activity (0.46 vs. 0.65 mM), but a higher Km for the transphosphatidylation activity (225 vs. 179 mM). These distinctive kinetic parameters suggest that SL PLD and SR PLD may be isoforms of the enzyme and/or have different membrane domain. Therefore, SL- and SR-localized PLD activities may be under independent control mechanism(s) and play distinct roles in normal conditions and pathological processes. Kluwer Academic Publishers, 1996 phospholipase D nationallicence hydrolysis nationallicence transphosphatidylation nationallicence sarcolemma nationallicence sarcoplasmic reticulum nationallicence heart nationallicence Dai Jian Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, 351 Tache Avenue, R2H 2A6, Winnipeg, Manitoba, Canada aut Liu Song-Yan Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, 351 Tache Avenue, R2H 2A6, Winnipeg, Manitoba, Canada aut Panagia Vincenzo Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, 351 Tache Avenue, R2H 2A6, Winnipeg, Manitoba, Canada aut Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 160-161/1(1996-03-01), 83-87 0300-8177 160-161:1<83 1996 160-161 11010 https://doi.org/10.1007/BF00240035 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00240035 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dai Jian Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, 351 Tache Avenue, R2H 2A6, Winnipeg, Manitoba, Canada aut NATIONALLICENCE 700 1- Liu Song-Yan Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, 351 Tache Avenue, R2H 2A6, Winnipeg, Manitoba, Canada aut NATIONALLICENCE 700 1- Panagia Vincenzo Division of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, 351 Tache Avenue, R2H 2A6, Winnipeg, Manitoba, Canada aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Kluwer Academic Publishers; http://www.wkap.nl 160-161/1(1996-03-01), 83-87 0300-8177 160-161:1<83 1996 160-161 11010 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer