ISSN:
1573-4986
Keywords:
Ca2+-ATPase
;
circular dichroism
;
fluorescence resonance energy transfer
;
ganglioside GM1 and GM3
;
membrane lipid fluidity
;
protein conformation
;
proteoliposomes
;
sarcoplasmic reticulum
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract On the basis of confirming the antagonistic effects of GM1 and GM3 on the activity of Ca2+-ATPase, we further demonstrated that some of the components of these two gangliosides, including sialic acid (NeuNAc), asialo-GM1, asialo-GM3 and ceramide, failed to show any effects on the activity of Ca2+-ATPase. Thus it is apparent that the intact molecules of these two gangliosides with their specific conformations were needed to perform their effects on Ca2+-ATPase. From the fluorescence resonance energy transfer measurements, the energy transfer between Cys 670/674 and Lys 515 was decreased by GM1 and increased by GM3, indicating GM1 induced the conformation of the hydrophilic region of Ca2+-ATPase to be less compact, while GM3 induced it to be more compact. From the CD spectra measurements, GM1 and GM3 both reduced the content of α-helical structures of Ca2+-ATPase, but GM1 caused a stronger decrease than that of GM3. Using DPH as the probe, we found that the membrane lipid fluidity of the proteoliposomes containing Ca2+-ATPase was decreased by GM1 and tend to increase by GM3.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1007123714104
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