Perchlorate-induced denaturation of ribonuclease A: Investigation of possible folding intermediates

Jm, Scholtz; Rl, Baldwin

doi:10.1021/bi00068a017

Cited by 25 publications

(20 citation statements)

References 39 publications

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“…A similar, although weaker, effect on the CD spectrum was observed by addition of perchlorate to unfolded RNase A. Here, a non-random CD spectrum was observed, but no protection of amide hydrogen bonds could be detected (Scholtz & Baldwin, 1993).…”

Section: Effect Of Tfe On B-structuresupporting

confidence: 76%

Native-like β-structure in a Trifluoroethanol-induced Partially Folded State of the All-β-sheet Protein Tendamistat

Schönbrunner

Wey

Engels

et al. 1996

Journal of Molecular Biology

109

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Section: Effect Of Tfe On B-structuresupporting

confidence: 76%

Native-like β-structure in a Trifluoroethanol-induced Partially Folded State of the All-β-sheet Protein Tendamistat

Schönbrunner

Wey

Engels

et al. 1996

Journal of Molecular Biology

109

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“…Although none show the complete set of features seen with our short uncharged helices, certain peptides and proteins exhibit perchlorate‐induced helicity changes 8. Certain denatured proteins that form molten globules at low pH values can show increased helicity in the presence of chaotropic anions such as perchlorate.…”

Section: Summary Of Salt and Acid Titration Data Derived From CD Specmentioning

confidence: 87%

Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry monitoring of anthocyanins in extracts from Arabidopsis thaliana leaves

Marczak

Kachlicki

Koźniewski

et al. 2008

Rapid Comm Mass Spectrometry

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Anthocyanins are secondary plant metabolites ubiquitous in the plant kingdom. They have different biological activities, so monitoring their content in plant tissue or in feed/food derived from plants may be an important task in different projects from various fields of molecular biology and biotechnology. Profiling of secondary metabolites with high-performance liquid chromatography/mass spectrometry (HPLC/MS) systems is time-consuming, especially when many samples have to be checked within a defined time frame with a reasonable number of repetitions according to the metabolomic standards. Even application of the advanced ultra-performance liquid chromatography (UPLC)/MS or equivalent systems would require a long time for analysis of numerous samples. We demonstrate the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the assessment of level (concentration) of anthocyanins in leaf tissues of four Arabidopsis thaliana ecotypes grown at normal (20 degrees C/16 degrees C day/night) and decreased (4 degrees C) temperature. The quantitative results were obtained for anthocyanins with MALDI-TOF MS using ferulic acid as a matrix. The amounts of anthocyanins in leaves of A. thaliana varied from 0.3-2.5 microg per gram of leaves for ecotypes Col-0 and C24, respectively, and contents of these markedly increased in plants grown in the cold. The applied analytical method exhibited better repeatability of measurements than obtained with an HPLC/ion trap MS system.

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“…The crystal structure of RNase A is known (10). The unfolding process was studied previously by static temperature methods (11)(12)(13), fluorescence (14), x-ray scattering and Fourier-transform IR (15,16), NMR (17)(18)(19)(20) and CD (21) spectroscopy. In denaturing, the native protein first relaxes toward an unfolded intermediate state, which then slowly equilibrates with more fully denatured structures.…”

mentioning

confidence: 99%

Ultrafast thermally induced unfolding of RNase A.

Phillips

Mizutani

Hochstrasser

1995

Proc. Natl. Acad. Sci. U.S.A.

193

181

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A temperature jump (T-jump) method capable of initiating thermally induced processes on the picosecond time scale in aqueous solutions is introduced. Protein solutions are heated by energy from a laser pulse that is absorbed by homogeneously dispersed molecules of the dye crystal violet. These act as transducers by releasing the energy as heat to cause a T-jump of up to 10 K with a time resolution of 70 ps. The method was applied to the unfolding of RNase A. At pH 5.7 and 59°C, a T-jump of 3-6 K induced unfolding which was detected by picosecond transient infrared spectroscopy of the amide I region between 1600 and 1700 cm-'.The difference spectral profile at 3.5 ns closely resembled that found for the equilibrium (native -unfolded) states. The signal at 1633 cm-1, corresponding to the fl-sheet structure, achieved 15 ± 2% of the decrease found at equilibrium, within 5.5 ns. However, no decrease in absorbance was detected until 1 ns after the T-jump. The disruption of fl-sheet therefore appears to be subject to a delay of -1 ns. Prior to 1 ns after the T-jump, water might be accessing the intact hydrophobic regions.Questions concerning the physical and chemical nature of protein folding are among the most challenging in biological research (1-4). Folding and unfolding events have seldom been studied on time scales shorter than milliseconds. Internal motions of macromolecules such as rotations about single bonds, chemical exchange reactions, diffusion over molecular dimensions, and barrier crossing processes can occur on nanosecond or even picosecond time scales, so protein structure reorganization might be expected to involve ultrafast intermediate steps. An example is the recent report of tens-ofmicroseconds folding in cytochrome c (5). Some of the faster processes in protein folding might involve relatively small alterations in electronic structure. Therefore the probes used to examine them must be sensitive to subtle changes in, for example, nonbonded interactions, weaker chemical bonds, charge distributions, and motions of pieces of the structure. For this reason we decided to use transient infrared (IR) spectroscopy (6-8), which is structure sensitive at a chemicalbond resolution, to identify any ultrafast folding steps.The IR spectra of proteins in the region of the amide vibrations of the polypeptide structures are well known to be sensitive to the state of the protein. For example, there are distinct differences between the IR spectra of random coil, a-helical, }3-sheet, 13'-sheet, and turn structures of polypeptides (9). These differences arise from the dependence of interactions between the various amide groups on the local polypeptide structures. One can therefore conceive of carrying out time-resolved IR capable of following the kinetics of structure change as it affects these different spatial regions of the polypeptide backbone. Experiments on the kinetics of folding also require that the system be triggered to suddenly change. For this purpose we have developed an ultrafast temperature jump...

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Perchlorate-induced denaturation of ribonuclease A: Investigation of possible folding intermediates

Cited by 25 publications

References 39 publications

Native-like β-structure in a Trifluoroethanol-induced Partially Folded State of the All-β-sheet Protein Tendamistat

Native-like β-structure in a Trifluoroethanol-induced Partially Folded State of the All-β-sheet Protein Tendamistat

Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry monitoring of anthocyanins in extracts from Arabidopsis thaliana leaves

Ultrafast thermally induced unfolding of RNase A.

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