| |
Records |
Links |
|
Author |
Abbruzzetti, S.; Viappiani, C.; Small, J.R.; Libertini, L.J.; Small, E.W. |
|
| |
Title |
Kinetics of histidine deligation from the heme in GuHCl-unfolded Fe(III) cytochrome C studied by a laser-induced pH-jump technique |
Type |
Journal Article |
| |
Year |
2001 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
|
| |
Volume |
123 |
Issue |
27 |
Pages |
6649-6653 |
|
| |
Keywords |
Animals; *Bacterial Proteins; Cytochrome c Group/*chemistry; Guanidine/*chemistry; Heme/*chemistry; Histidine/*chemistry; Horses; Hydrogen-Ion Concentration; Kinetics; *Lasers; Ligands; Protein Folding |
|
| |
Abstract  |
We have developed an instrumental setup that uses transient absorption to monitor protein folding/unfolding processes following a laser-induced, ultrafast release of protons from o-nitrobenzaldehyde. The resulting increase in [H(+)], which can be more than 100 microM, is complete within a few nanoseconds. The increase in [H(+)] lowers the pH of the solution from neutrality to approximately 4 at the highest laser pulse energy used. Protein structural rearrangements can be followed by transient absorption, with kinetic monitoring over a broad time range (approximately 10 ns to 500 ms). Using this pH-jump/transient absorption technique, we have examined the dissociation kinetics of non-native axial heme ligands (either histidine His26 or His33) in GuHCl-unfolded Fe(III) cytochrome c (cyt c). Deligation of the non-native ligands following the acidic pH-jump occurs as a biexponential process with different pre-exponential factors. The pre-exponential factors markedly depend on the extent of the pH-jump, as expected from differences in the pK(a) values of His26 and His33. The two lifetimes were found to depend on temperature but were not functions of either the magnitude of the pH-jump or the pre-pulse pH of the solution. The activation energies of the deligation processes support the suggestion that GuHCl-unfolded cyt c structures with non-native histidine axial ligands represent kinetic traps in unfolding. |
|
| |
Address |
Dipartimento di Fisica, Universita di Parma, Istituto Nazionale per la Fisica della Materia, 43100 Parma, Italy |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0002-7863 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:11439052 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3788 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Abbruzzetti, S.; Crema, E.; Masino, L.; Vecli, A.; Viappiani, C.; Small, J.R.; Libertini, L.J.; Small, E.W. |
|
| |
Title |
Fast events in protein folding: structural volume changes accompanying the early events in the N-->I transition of apomyoglobin induced by ultrafast pH jump |
Type |
Journal Article |
| |
Year |
2000 |
Publication |
Biophysical Journal |
Abbreviated Journal |
Biophys J |
|
| |
Volume |
78 |
Issue |
1 |
Pages |
405-415 |
|
| |
Keywords |
Animals; Apoproteins/*chemistry; Horses; *Hydrogen-Ion Concentration; Kinetics; Models, Molecular; Myoglobin/*chemistry; Protein Conformation; *Protein Folding; Protein Structure, Secondary; Spectrometry, Fluorescence |
|
| |
Abstract |
Ultrafast, laser-induced pH jump with time-resolved photoacoustic detection has been used to investigate the early protonation steps leading to the formation of the compact acid intermediate (I) of apomyoglobin (ApoMb). When ApoMb is in its native state (N) at pH 7.0, rapid acidification induced by a laser pulse leads to two parallel protonation processes. One reaction can be attributed to the binding of protons to the imidazole rings of His24 and His119. Reaction with imidazole leads to an unusually large contraction of -82 +/- 3 ml/mol, an enthalpy change of 8 +/- 1 kcal/mol, and an apparent bimolecular rate constant of (0.77 +/- 0.03) x 10(10) M(-1) s(-1). Our experiments evidence a rate-limiting step for this process at high ApoMb concentrations, characterized by a value of (0. 60 +/- 0.07) x 10(6) s(-1). The second protonation reaction at pH 7. 0 can be attributed to neutralization of carboxylate groups and is accompanied by an apparent expansion of 3.4 +/- 0.2 ml/mol, occurring with an apparent bimolecular rate constant of (1.25 +/- 0.02) x 10(11) M(-1) s(-1), and a reaction enthalpy of about 2 kcal/mol. The activation energy for the processes associated with the protonation of His24 and His119 is 16.2 +/- 0.9 kcal/mol, whereas that for the neutralization of carboxylates is 9.2 +/- 0.9 kcal/mol. At pH 4.5 ApoMb is in a partially unfolded state (I) and rapid acidification experiments evidence only the process assigned to carboxylate protonation. The unusually large contraction and the high energetic barrier observed at pH 7.0 for the protonation of the His residues suggests that the formation of the compact acid intermediate involves a rate-limiting step after protonation. |
|
| |
Address |
Dipartimento di Fisica, Universita di Parma, 43100 Parma, Italia |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0006-3495 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:10620304 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3792 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gulotta, M.; Rogatsky, E.; Callender, R.H.; Dyer, R.B. |
|
| |
Title |
Primary folding dynamics of sperm whale apomyoglobin: core formation |
Type |
Journal Article |
| |
Year |
2003 |
Publication |
Biophysical Journal |
Abbreviated Journal |
Biophys J |
|
| |
Volume |
84 |
Issue |
3 |
Pages |
1909-1918 |
|
| |
Keywords |
Animals; Apoproteins/*chemistry; Crystallography/*methods; Horses; Myocardium/chemistry; Myoglobin/*chemistry; Protein Conformation; *Protein Folding; Species Specificity; Structure-Activity Relationship; Temperature; Whales |
|
| |
Abstract |
The structure, thermodynamics, and kinetics of heat-induced unfolding of sperm whale apomyoglobin core formation have been studied. The most rudimentary core is formed at pH(*) 3.0 and up to 60 mM NaCl. Steady state for ultraviolet circular dichroism and fluorescence melting studies indicate that the core in this acid-destabilized state consists of a heterogeneous composition of structures of approximately 26 residues, two-thirds of the number involved for horse heart apomyoglobin under these conditions. Fluorescence temperature-jump relaxation studies show that there is only one process involved in Trp burial. This occurs in 20 micro s for a 7 degrees jump to 52 degrees C, which is close to the limits placed by diffusion on folding reactions. However, infrared temperature jump studies monitoring native helix burial are biexponential with times of 5 micro s and 56 micro s for a similar temperature jump. Both fluorescence and infrared fast phases are energetically favorable but the slow infrared absorbance phase is highly temperature-dependent, indicating a substantial enthalpic barrier for this process. The kinetics are best understood by a multiple-pathway kinetics model. The rapid phases likely represent direct burial of one or both of the Trp residues and parts of the G- and H-helices. We attribute the slow phase to burial and subsequent rearrangement of a misformed core or to a collapse having a high energy barrier wherein both Trps are solvent-exposed. |
|
| |
Address |
Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA. gulotta@aecom.yu.edu |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0006-3495 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:12609893 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3783 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chiba, K.; Ikai, A.; Kawamura-Konishi, Y.; Kihara, H. |
|
| |
Title |
Kinetic study on myoglobin refolding monitored by five optical probe stopped-flow methods |
Type |
Journal Article |
| |
Year |
1994 |
Publication |
Proteins |
Abbreviated Journal |
Proteins |
|
| |
Volume |
19 |
Issue |
2 |
Pages |
110-119 |
|
| |
Keywords |
Animals; Chromatography, Gel; Circular Dichroism; Horses; Kinetics; Metmyoglobin/analogs & derivatives/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Urea |
|
| |
Abstract |
The refolding kinetics of horse cyanometmyoglobin induced by concentration jump of urea was investigated by five optical probe stopped-flow methods: absorption at 422 nm, tryptophyl fluorescence at around 340 nm, circular dichroism (CD) at 222 nm, CD at 260 nm, and CD at 422 nm. In the refolding process, we detected three phases with rate constants of > 1 x 10(2) s-1, (4.5-9.3) s-1, and (2-5) x 10(-3) s-1. In the fastest phase, a substantial amount of secondary structure (approximately 40%) is formed within the dead time of the CD stopped-flow apparatus (10.7 ms). The kinetic intermediate populated in the fastest phase is shown to capture a hemindicyanide, suggesting that a “heme pocket precursor” recognized by hemindicyanide must be constructed within the dead time. In the middle phase, most of secondary and tertiary structures, especially around the captured hemindicyanide, have been constructed. In the slowest phase, we detected a minor structural rearrangement accompanying the ligand-exchange reaction in the fifth coordination of ferric iron. We present a possible model for the refolding process of myoglobin in the presence of the heme group. |
|
| |
Address |
Laboratory of Biodynamics, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Kanagawa, Japan |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0887-3585 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:8090705 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3799 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Ballew, R.M.; Sabelko, J.; Gruebele, M. |
|
| |
Title |
Direct observation of fast protein folding: the initial collapse of apomyoglobin |
Type |
Journal Article |
| |
Year |
1996 |
Publication |
Proceedings of the National Academy of Sciences of the United States of America |
Abbreviated Journal |
Proc. Natl. Acad. Sci. U.S.A. |
|
| |
Volume |
93 |
Issue |
12 |
Pages |
5759-5764 |
|
| |
Keywords |
Animals; Apoproteins/*chemistry; Circular Dichroism; Horses; Kinetics; Muscle, Skeletal/chemistry; Myoglobin/*chemistry; *Protein Folding; Spectrometry, Fluorescence; Spectrophotometry, Infrared; Temperature |
|
| |
Abstract |
The rapid refolding dynamics of apomyoglobin are followed by a new temperature-jump fluorescence technique on a 15-ns to 0.5-ms time scale in vitro. The apparatus measures the protein-folding history in a single sweep in standard aqueous buffers. The earliest steps during folding to a compact state are observed and are complete in under 20 micros. Experiments on mutants and consideration of steady-state CD and fluorescence spectra indicate that the observed microsecond phase monitors assembly of an A x (H x G) helix subunit. Measurements at different viscosities indicate diffusive behavior even at low viscosities, in agreement with motions of a solvent-exposed protein during the initial collapse. |
|
| |
Address |
School of Chemical Sciences and Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, 61801, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0027-8424 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:8650166 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3798 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Polverini, E.; Cugini, G.; Annoni, F.; Abbruzzetti, S.; Viappiani, C.; Gensch, T. |
|
| |
Title |
Molten globule formation in apomyoglobin monitored by the fluorescent probe Nile Red |
Type |
Journal Article |
| |
Year |
2006 |
Publication |
Biochemistry |
Abbreviated Journal |
Biochemistry |
|
| |
Volume |
45 |
Issue |
16 |
Pages |
5111-5121 |
|
| |
Keywords |
Animals; Apoproteins/*chemistry/*metabolism; Binding Sites; Computer Simulation; Fluorescent Dyes/analysis; Horses; Hydrogen-Ion Concentration; Models, Molecular; Myoglobin/*chemistry/*metabolism; Oxazines/*analysis/chemistry; Protein Binding; Protein Folding; Protein Structure, Tertiary |
|
| |
Abstract |
The interaction of nile red (NR) with apomyoglobin (ApoMb) in the native (pH 7) and molten globule (pH 4) states was investigated using experimental and computational methods. NR binds to hydrophobic locations in ApoMb with higher affinity (K(d) = 25 +/- 5 microM) in the native state than in the molten globule state (K(d) = 52 +/- 5 microM). In the molten globule state, NR is located in a more hydrophobic environment. The dye does not bind to the holoprotein, suggesting that the binding site is located at the heme pocket. In addition to monitoring steady-state properties, the fluorescence emission of NR is capable of tracking submillisecond, time-resolved structural rearrangements of the protein, induced by a nanosecond pH jump. Molecular dynamics simulations were run on ApoMb at neutral pH and at pH 4. The structure obtained for the molten globule state is consistent with the experimentally available structural data. The docking of NR with the crystal structure shows that the ligand binds into the binding pocket of the heme group, with an orientation bringing the planar ring system of NR to overlap with the position of two of the heme porphyrin rings in Mb. The docking of NR with the ApoMb structure at pH 4 shows that the dye binds to the heme pocket with a slightly less favorable binding energy, in keeping with the experimental K(d) value. Under these conditions, NR is positioned in a different orientation, reaching a more hydrophobic environment in agreement with the spectroscopic data. |
|
| |
Address |
Dipartimento di Fisica, Universita degli Studi di Parma, Viale G. P. Usberti 7/A, 43100 Parma, Italy |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0006-2960 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:16618100 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3763 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Hagen, S.J.; Eaton, W.A. |
|
| |
Title |
Two-state expansion and collapse of a polypeptide |
Type |
Journal Article |
| |
Year |
2000 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
|
| |
Volume |
301 |
Issue |
4 |
Pages |
1019-1027 |
|
| |
Keywords |
Animals; Computer Simulation; Cytochrome c Group/*chemistry/*metabolism; Horses; Kinetics; Lasers; Models, Chemical; Peptides/*chemistry/*metabolism; Protein Conformation; Protein Denaturation; *Protein Folding; Spectrometry, Fluorescence; Temperature; Thermodynamics |
|
| |
Abstract |
The initial phase of folding for many proteins is presumed to be the collapse of the polypeptide chain from expanded to compact, but still denatured, conformations. Theory and simulations suggest that this collapse may be a two-state transition, characterized by barrier-crossing kinetics, while the collapse of homopolymers is continuous and multi-phasic. We have used a laser temperature-jump with fluorescence spectroscopy to measure the complete time-course of the collapse of denatured cytochrome c with nanosecond time resolution. We find the process to be exponential in time and thermally activated, with an apparent activation energy approximately 9 k(B)T (after correction for solvent viscosity). These results indicate that polypeptide collapse is kinetically a two-state transition. Because of the observed free energy barrier, the time scale of polypeptide collapse is dramatically slower than is predicted by Langevin models for homopolymer collapse. |
|
| |
Address |
Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Building 5, Bethesda, MD, 20892-0520, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-2836 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:10966803 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3790 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mizuguchi, M.; Arai, M.; Ke, Y.; Nitta, K.; Kuwajima, K. |
|
| |
Title |
Equilibrium and kinetics of the folding of equine lysozyme studied by circular dichroism spectroscopy |
Type |
Journal Article |
| |
Year |
1998 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
|
|
| |
Volume |
283 |
Issue |
1 |
Pages |
265-277 |
|
| |
Keywords |
equine lysozyme; protein folding; molten globule; stopped-flow; folding intermediate |
|
| |
Abstract |
The equilibrium unfolding and the kinetics of unfolding and refolding of equine lysozyme, a Ca2+-binding protein, were studied by means of circular dichroism spectra in the far and near-ultraviolet regions. The transition curves of the guanidine hydrochloride-induced unfolding measured at 230 nm and 292.5 nm, and for the apo and holo forms of the protein have shown that the unfolding is well represented by a three-state mechanism in which the molten globule state is populated as a stable intermediate. The molten globule state of this protein is more stable and more native-like than that of α-lactalbumin, a homologous protein of equine lysozyme. The kinetic unfolding and refolding of the protein were induced by concentration jumps of the denaturant and measured by stopped-flow circular dichroism. The observed unfolding and refolding curves both agreed well with a single-exponential function. However, in the kinetic refolding reactions below 3 M guanidine hydrochloride, a burst-phase change in the circular dichroism was present, and the burst-phase intermediate in the kinetic refolding is shown to be identical with the molten globule state observed in the equilibrium unfolding. Under a strongly native condition, virtually all the molecules of equine lysozyme transform the structure from the unfolded state into the molten globule, and the subsequent refolding takes place from the molten globule state. The transition state of folding, which may exist between the molten globule and the native states, was characterized by investigating the guanidine hydrochloride concentration-dependence of the rate constants of refolding and unfolding. More than 80% of the hydrophobic surface of the protein is buried in the transition state, so that it is much closer to the native state than to the molten globule in which only 36% of the surface is buried in the interior of the molecule. It is concluded that all the present results are best explained by a sequential model of protein folding, in which the molten globule state is an obligatory folding intermediate on the pathway of folding. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3990 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Pierce, M.M.; Nall, B.T. |
|
| |
Title |
Coupled kinetic traps in cytochrome c folding: His-heme misligation and proline isomerization |
Type |
Journal Article |
| |
Year |
2000 |
Publication |
Journal of Molecular Biology |
Abbreviated Journal |
J Mol Biol |
|
| |
Volume |
298 |
Issue |
5 |
Pages |
955-969 |
|
| |
Keywords |
Amino Acid Sequence; Amino Acid Substitution/genetics; Binding Sites; Cytochrome c Group/*chemistry/genetics/*metabolism; *Cytochromes c; Enzyme Stability/drug effects; Fluorescence; Guanidine/pharmacology; Heme/*metabolism; Histidine/genetics/*metabolism; Hydrogen-Ion Concentration; Isomerism; Kinetics; Models, Molecular; Molecular Sequence Data; Mutation/genetics; Proline/*chemistry/metabolism; Protein Conformation/drug effects; Protein Denaturation/drug effects; *Protein Folding; Protein Renaturation; Saccharomyces cerevisiae/enzymology/genetics; Sequence Alignment; Thermodynamics |
|
| |
Abstract |
The effect of His-heme misligation on folding has been investigated for a triple mutant of yeast iso-2 cytochrome c (N26H,H33N,H39K iso-2). The variant contains a single misligating His residue at position 26, a location at which His residues are found in several cytochrome c homologues, including horse, tuna, and yeast iso-1. The amplitude for fast phase folding exhibits a strong initial pH dependence. For GdnHCl unfolded protein at an initial pH<5, the observed refolding at final pH 6 is dominated by a fast phase (tau(2f)=20 ms, alpha(2f)=90 %) that represents folding in the absence of misligation. For unfolded protein at initial pH 6, folding at final pH 6 occurs in a fast phase of reduced amplitude (alpha(2f) approximately 20 %) but the same rate (tau(2f)=20 ms), and in two slower phases (tau(m)=6-8 seconds, alpha(m) approximately 45 %; and tau(1b)=16-20 seconds, alpha(1b) approximately 35 %). Double jump experiments show that the initial pH dependence of the folding amplitudes results from a slow pH-dependent equilibrium between fast and slow folding species present in the unfolded protein. The slow equilibrium arises from coupling of the His protonation equilibrium to His-heme misligation and proline isomerization. Specifically, Pro25 is predominantly in trans in the unligated low-pH unfolded protein, but is constrained in a non-native cis isomerization state by His26-heme misligation near neutral pH. Refolding from the misligated unfolded form proceeds slowly due to the large energetic barrier required for proline isomerization and displacement of the misligated His26-heme ligand. |
|
| |
Address |
Center for Biomolecular Structure, Department of Biochemistry, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0022-2836 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:10801361 |
Approved |
no |
|
| |
Call Number |
refbase @ user @ |
Serial |
3853 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gilmanshin, R.; Callender, R.H.; Dyer, R.B. |
|
| |
Title |
The core of apomyoglobin E-form folds at the diffusion limit |
Type |
Journal Article |
| |
Year |
1998 |
Publication |
Nature Structural Biology |
Abbreviated Journal |
Nat Struct Biol |
|
| |
Volume |
5 |
Issue |
5 |
Pages |
363-365 |
|
| |
Keywords |
Animals; Apoproteins/*chemistry; Diffusion; Horses; Myoglobin/*chemistry; *Protein Folding; Spectroscopy, Fourier Transform Infrared; Temperature |
|
| |
Abstract |
The E-form of apomyoglobin has been characterized using infrared and fluorescence spectroscopies, revealing a compact core with native like contacts, most probably consisting of 15-20 residues of the A, G and H helices of apomyoglobin. Fast temperature-jump, time-resolved infrared measurements reveal that the core is formed within 96 micros at 46 degrees C, close to the diffusion limit for loop formation. Remarkably, the folding pathway of the E-form is such that the formation of a limited number of native-like contacts is not rate limiting, or that the contacts form on the same time scale expected for diffusion controlled loop formation. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
English |
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1072-8368 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
PMID:9586997 |
Approved |
no |
|
| |
Call Number |
Equine Behaviour @ team @ |
Serial |
3795 |
|
| Permanent link to this record |
