The structures of the active center in dark-adapted bacteriorhodopsin by solution-state NMR spectroscopy.
نویسندگان
چکیده
The two forms of bacteriorhodopsin present in the dark-adapted state, containing either all-trans or 13-cis,15-syn retinal, were examined by using solution state NMR, and their structures were determined. Comparison of the all-trans and the 13-cis,15-syn forms shows a shift in position of about 0.25 A within the pocket of the protein. Comparing this to the 13-cis,15-anti chromophore of the catalytic cycle M-intermediate structure, the 13-cis,15-syn form demonstrates a less pronounced up-tilt of the retinal C12[bond]C14 region, while leaving W182 and T178 essentially unchanged. The N[bond]H dipole of the Schiff base orients toward the extracellular side in both forms, however, it reorients toward the intracellular side in the 13-cis,15-anti configuration to form the catalytic M-intermediate. Thus, the change of the N[bond]H dipole is considered primarily responsible for energy storage, conformation changes of the protein, and the deprotonation of the Schiff base. The structural similarity of the all-trans and 13-cis,15-syn forms is taken as strong evidence for the ion dipole dragging model by which proton (hydroxide ion) translocation follows the change of the dipole.
منابع مشابه
Fourier transform infrared difference spectroscopy of bacteriorhodopsin and its photoproducts.
Fourier transform infrared difference spectroscopy has been used to obtain the vibrational modes in the chromophore and apoprotein that change in intensity or position between light-adapted bacteriorhodopsin and the K and M intermediates in its photocycle and between dark-adapted and light-adapted bacteriorhodopsin. Our infrared measurements provide independent verification of resonance Raman r...
متن کاملSolvent Effect on the Molecular Structure, Chemical Reactivity and Spectroscopy Properties of Z-Ligustilide: A Main Active Component of Multitude Umbelliferae Medicinal Plants
In this investigation, the structural, electronic properties, 13C and 1H NMR parameters and firsthyperpolarizability of Z-Ligustilide were explored. As well, the solvent effect on structural parameters, frontier orbital energies, electronic transitions, and 13C and 1H NMR parameters was illustrated based on Polarizable Continuum Model (PCM).These consequences specify that the polarity of solven...
متن کاملTryptophan interactions in bacteriorhodopsin: a heteronuclear solid-state NMR study.
The bulky and amphiphilic nature of tryptophan residues makes them particularly interesting components of proteins. In bacteriorhodopsin, four of the eight tryptophan residues are in the active site, forming parts of the retinal binding pocket. In this work, we use solid-state NMR to study the interactions of the tryptophan residues in wild-type bacteriorhodopsin, in the resting state, and in c...
متن کاملOptical and Nano structural properties of Hematite (α-Fe2O3) nanorods in interaction with Bovine Serum Albumin (BSA) Protein Solution
Hematite (α-Fe2O3) nanorods were synthesized by hydrothermal method using Cetyltrimethylammonium bromide (CTAB) as a surfactant agent. To study optical, nanostructural properties, and to control the morphology and shape of nanorods, 0.025 mol L-1, 0.05 mol L-1 and 0.1 mol L-1 concentration of CTAB were used. Moreover, the effect of interaction between bovine serum albumin (BSA) A9418-5G protein...
متن کاملFunctional and shunt states of bacteriorhodopsin resolved by 250 GHz dynamic nuclear polarization-enhanced solid-state NMR.
Observation and structural studies of reaction intermediates of proteins are challenging because of the mixtures of states usually present at low concentrations. Here, we use a 250 GHz gyrotron (cyclotron resonance maser) and cryogenic temperatures to perform high-frequency dynamic nuclear polarization (DNP) NMR experiments that enhance sensitivity in magic-angle spinning NMR spectra of cryo-tr...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 99 15 شماره
صفحات -
تاریخ انتشار 2002