Abstract
Adenylate cyclase from bovine brain cortex was reconstituted into asolectin liposomes with (500-fold) or without transmembrane Ca2+ gradient. The enzyme activity of four types of proteoliposomes (the active center of enzyme exposing outside) was compared. The highest adenylate cyclase activity was observed in the vesicles with outside lower Ca2+ concentration (approximately 10(-6) mol/L, similar to the physiological condition). If the transmembrane Ca2+ gradient was in the inverse direction (i.e. outside higher Ca2+ concentration, 0.5 mmol/L), a lowest enzymatic activity would appear. The difference in enzymatic activity between the two types of proteoliposomes could be diminished following the addition of Ca2+ ionophore A23187. Proteoliposomes without transmembrane Ca2+ gradient exhibited intermediate activities. The conformation difference of adenylate cyclases in the above-mentioned proteoliposomes was also detected by measuring intrinsic fluorescence and fluorescence quenching with KI.
| Original language | English |
|---|---|
| Pages (from-to) | 67-75 |
| Number of pages | 9 |
| Journal | Science in China. Series B, Chemistry, life sciences & earth sciences |
| Volume | 35 |
| Issue number | 1 |
| State | Published - Jan 1992 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Medicine(all)
Cite this
Effect of transmembrane Ca2+ gradient on conformation and enzyme activity of reconstituted adenylate cyclase. / Tu, Y. P.; Yang, F. Y.
In: Science in China. Series B, Chemistry, life sciences & earth sciences, Vol. 35, No. 1, 01.1992, p. 67-75.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of transmembrane Ca2+ gradient on conformation and enzyme activity of reconstituted adenylate cyclase.
AU - Tu, Y. P.
AU - Yang, F. Y.
PY - 1992/1
Y1 - 1992/1
N2 - Adenylate cyclase from bovine brain cortex was reconstituted into asolectin liposomes with (500-fold) or without transmembrane Ca2+ gradient. The enzyme activity of four types of proteoliposomes (the active center of enzyme exposing outside) was compared. The highest adenylate cyclase activity was observed in the vesicles with outside lower Ca2+ concentration (approximately 10(-6) mol/L, similar to the physiological condition). If the transmembrane Ca2+ gradient was in the inverse direction (i.e. outside higher Ca2+ concentration, 0.5 mmol/L), a lowest enzymatic activity would appear. The difference in enzymatic activity between the two types of proteoliposomes could be diminished following the addition of Ca2+ ionophore A23187. Proteoliposomes without transmembrane Ca2+ gradient exhibited intermediate activities. The conformation difference of adenylate cyclases in the above-mentioned proteoliposomes was also detected by measuring intrinsic fluorescence and fluorescence quenching with KI.
AB - Adenylate cyclase from bovine brain cortex was reconstituted into asolectin liposomes with (500-fold) or without transmembrane Ca2+ gradient. The enzyme activity of four types of proteoliposomes (the active center of enzyme exposing outside) was compared. The highest adenylate cyclase activity was observed in the vesicles with outside lower Ca2+ concentration (approximately 10(-6) mol/L, similar to the physiological condition). If the transmembrane Ca2+ gradient was in the inverse direction (i.e. outside higher Ca2+ concentration, 0.5 mmol/L), a lowest enzymatic activity would appear. The difference in enzymatic activity between the two types of proteoliposomes could be diminished following the addition of Ca2+ ionophore A23187. Proteoliposomes without transmembrane Ca2+ gradient exhibited intermediate activities. The conformation difference of adenylate cyclases in the above-mentioned proteoliposomes was also detected by measuring intrinsic fluorescence and fluorescence quenching with KI.
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M3 - Article
VL - 35
SP - 67
EP - 75
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 - 1
ER -