作者: J L Arrondo , H H Mantsch , N Mullner , S Pikula , A Martonosi
DOI: 10.1016/S0021-9258(18)48043-X
关键词: Calcium ATPase 、 Protein secondary structure 、 Vesicle 、 Vanadate 、 Fourier transform infrared spectroscopy 、 Crystallography 、 Biochemistry 、 Endoplasmic reticulum 、 Infrared spectroscopy 、 Chemistry 、 Membrane lipids
摘要: Abstract The Ca2+-transporting ATPase (EC 3.6.1.38) of sarcoplasmic reticulum alternates between several conformational states during ATP-dependent Ca2+ transport. E1 conformation is stabilized by 0.1 mM and the E2 vanadate in a Ca2+-free medium. Fourier transform infrared spectroscopy reveals significant differences two that indicate protein secondary structure. corresponding spectra can be interconverted reversibly changing concentration spectral changes appearance new alpha-helical substructure connected with E1----E2 conversion accompanied small beta-turns, while beta-sheet content remains essentially unchanged. There are also C = O stretching vibrations ester carbonyl groups phospholipids intact not observed under identical conditions isolated lipid dispersions. These observations imply an effect proteins on structure interfacial regions dependent state Ca2+-ATPase. CH2- CH3-stretching frequencies membrane lipids affected significantly transition. vesicles presence 20 suggest stabilization similar to except for behavior COO- phospholipid may reflect charge effects bound Ca2+.