Transmembrane Ca2+ gradient-mediated phosphatidylcholine modulating sarcoplasmic reticulum C(a2+)-ATPase.

Y. Tu, H. Xu, F. Yang

Research output: Contribution to journalArticle

Abstract

The sarcoplasmic reticulum (SR) C(a2+)-ATPase was purified and reconstituted into the sealed phospholipids vesicles with or without transmembrane Ca2+ gradient. The role of phospholipids, especially phosphatidylcholine (PC), in the modulation of C(a2+)-ATPase by transmembrane Ca2+ gradient was investigated. The results are as follows. (i) Incubated with phospholipids, the enzyme activity of the delipidated C(a2+)-ATPase is inhibited by Ca2+ and the highest inhibition is observed in the presence of PC. (ii) When there exists a transmembrane Ca2+ gradient (higher Ca2+ concentration inside vesicles, 1,000 mumol/L:50 mumol/L, similar to the physiological condition), the inhibition of C(a2+)-ATPase by transmembrane Ca2+ gradient can be only observed in the vesicles containing PC:PE, but not in those containing PS:PE or PG:PE. The highest inhibition is obtained at a 50:50 molar ratio of PC:PE (iii) By comparing the effects of PC differing in acyl chains, higher inhibition of C(a2+)-ATPase is observed in vesicles containing DPPC:PE and DOPC:PE, while no inhibition in DMPC:PE vesicles (iv) If the transmembrane Ca2+ gradient is in the inverse direction, the enzyme activity of C(a2+)-ATPase is inhibited whenever reconstituted with acidic or neutral phospholipids.

Original languageEnglish
Pages (from-to)713-721
Number of pages9
JournalScience in China. Series B, Chemistry, life sciences & earth sciences
Volume38
Issue number6
StatePublished - Jun 1995
Externally publishedYes

Fingerprint

Sarcoplasmic Reticulum
vesicle
Phosphatidylcholines
Adenosine Triphosphatases
phospholipid
Phospholipids
Calcium-Transporting ATPases
Enzyme activity
enzyme activity
Dimyristoylphosphatidylcholine
Enzymes
Modulation

All Science Journal Classification (ASJC) codes

  • Medicine(all)

Cite this

@article{775fc1c411084045bb2e180ad5803b79,
title = "Transmembrane Ca2+ gradient-mediated phosphatidylcholine modulating sarcoplasmic reticulum C(a2+)-ATPase.",
abstract = "The sarcoplasmic reticulum (SR) C(a2+)-ATPase was purified and reconstituted into the sealed phospholipids vesicles with or without transmembrane Ca2+ gradient. The role of phospholipids, especially phosphatidylcholine (PC), in the modulation of C(a2+)-ATPase by transmembrane Ca2+ gradient was investigated. The results are as follows. (i) Incubated with phospholipids, the enzyme activity of the delipidated C(a2+)-ATPase is inhibited by Ca2+ and the highest inhibition is observed in the presence of PC. (ii) When there exists a transmembrane Ca2+ gradient (higher Ca2+ concentration inside vesicles, 1,000 mumol/L:50 mumol/L, similar to the physiological condition), the inhibition of C(a2+)-ATPase by transmembrane Ca2+ gradient can be only observed in the vesicles containing PC:PE, but not in those containing PS:PE or PG:PE. The highest inhibition is obtained at a 50:50 molar ratio of PC:PE (iii) By comparing the effects of PC differing in acyl chains, higher inhibition of C(a2+)-ATPase is observed in vesicles containing DPPC:PE and DOPC:PE, while no inhibition in DMPC:PE vesicles (iv) If the transmembrane Ca2+ gradient is in the inverse direction, the enzyme activity of C(a2+)-ATPase is inhibited whenever reconstituted with acidic or neutral phospholipids.",
author = "Y. Tu and H. Xu and F. Yang",
year = "1995",
month = "6",
language = "English",
volume = "38",
pages = "713--721",
journal = "Science in China. Series B, Chemistry, life sciences & earth sciences",
issn = "1001-652X",
publisher = "Science in China Press",
number = "6",

}

TY - JOUR

T1 - Transmembrane Ca2+ gradient-mediated phosphatidylcholine modulating sarcoplasmic reticulum C(a2+)-ATPase.

AU - Tu, Y.

AU - Xu, H.

AU - Yang, F.

PY - 1995/6

Y1 - 1995/6

N2 - The sarcoplasmic reticulum (SR) C(a2+)-ATPase was purified and reconstituted into the sealed phospholipids vesicles with or without transmembrane Ca2+ gradient. The role of phospholipids, especially phosphatidylcholine (PC), in the modulation of C(a2+)-ATPase by transmembrane Ca2+ gradient was investigated. The results are as follows. (i) Incubated with phospholipids, the enzyme activity of the delipidated C(a2+)-ATPase is inhibited by Ca2+ and the highest inhibition is observed in the presence of PC. (ii) When there exists a transmembrane Ca2+ gradient (higher Ca2+ concentration inside vesicles, 1,000 mumol/L:50 mumol/L, similar to the physiological condition), the inhibition of C(a2+)-ATPase by transmembrane Ca2+ gradient can be only observed in the vesicles containing PC:PE, but not in those containing PS:PE or PG:PE. The highest inhibition is obtained at a 50:50 molar ratio of PC:PE (iii) By comparing the effects of PC differing in acyl chains, higher inhibition of C(a2+)-ATPase is observed in vesicles containing DPPC:PE and DOPC:PE, while no inhibition in DMPC:PE vesicles (iv) If the transmembrane Ca2+ gradient is in the inverse direction, the enzyme activity of C(a2+)-ATPase is inhibited whenever reconstituted with acidic or neutral phospholipids.

AB - The sarcoplasmic reticulum (SR) C(a2+)-ATPase was purified and reconstituted into the sealed phospholipids vesicles with or without transmembrane Ca2+ gradient. The role of phospholipids, especially phosphatidylcholine (PC), in the modulation of C(a2+)-ATPase by transmembrane Ca2+ gradient was investigated. The results are as follows. (i) Incubated with phospholipids, the enzyme activity of the delipidated C(a2+)-ATPase is inhibited by Ca2+ and the highest inhibition is observed in the presence of PC. (ii) When there exists a transmembrane Ca2+ gradient (higher Ca2+ concentration inside vesicles, 1,000 mumol/L:50 mumol/L, similar to the physiological condition), the inhibition of C(a2+)-ATPase by transmembrane Ca2+ gradient can be only observed in the vesicles containing PC:PE, but not in those containing PS:PE or PG:PE. The highest inhibition is obtained at a 50:50 molar ratio of PC:PE (iii) By comparing the effects of PC differing in acyl chains, higher inhibition of C(a2+)-ATPase is observed in vesicles containing DPPC:PE and DOPC:PE, while no inhibition in DMPC:PE vesicles (iv) If the transmembrane Ca2+ gradient is in the inverse direction, the enzyme activity of C(a2+)-ATPase is inhibited whenever reconstituted with acidic or neutral phospholipids.

UR - http://www.scopus.com/inward/record.url?scp=0029315950&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029315950&partnerID=8YFLogxK

M3 - Article

C2 - 7626201

VL - 38

SP - 713

EP - 721

JO - Science in China. Series B, Chemistry, life sciences & earth sciences

JF - Science in China. Series B, Chemistry, life sciences & earth sciences

SN - 1001-652X

IS - 6

ER -