Proteins at Work: “Stop-Action” Pictures at Subzero Temperatures

Douzou, Pierre; Petsko, Gregory A.

doi:10.1016/s0065-3233(08)60299-5

Cited by 110 publications

(104 citation statements)

References 99 publications

Supporting

Mentioning

101

Contrasting

Unclassified

Order By: Relevance

“…A mixture of DMSO and water (20:80, v:v, corresponding to a DMSO mole fraction of 0.050) has viscosities of 1.5^2.8 cp in the temperature range 293^273 K. The same viscosity, 1.5 cp at 293 K, is obtained by mixing glycerol, a normal component of the membrane heads and well-known osmolyte [18], with water to get a glycerol mole fraction of 0.036. 15 N-Edited NOESY [13] spectra of 15 N-labelled [Leu]enkephalin in the mixture of water and DMSO, show an outstanding di¡erence between bulk solvent and gel phase, in the temperature range 273 to 293 K. Cross peaks are absent in the spectrum in bulk solvent at a temperature of 293 K and very few appear at 273 K whereas the spectrum in gel at 293 K has the same number of visible cross peaks of the spectrum in bulk at 273 K, i.e. the actual viscosity of the gel phase should be close to 2.8 cp.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

NMR studies of flexible peptides in cavities mimicking the synaptic cleft

et al. 2002

View full text Add to dashboard Cite

The interaction of neuropeptides with post-synaptic receptors is characterised by a high entropic barrier originating from the combination of nanomolar concentration with low conformer population. The influence of high viscosity environments on conformer distribution can help overcome this difficulty. In an attempt to simulate the physicochemical conditions of the synaptic cleft, 15 N-labelled enkephalin has been studied in polyacrylamide gels swollen by different aqueous solutions in the temperature range 273^293 K. Nuclear Overhauser enhancement spectra in the gel pores are consistent with a conformational selection or a slowing down of internal motions that can favour the interaction of the peptide with the receptor. ß

show abstract

Section: Resultsmentioning

confidence: 99%

“…Two-dimensional heteronuclear single quantum coherence experiments were recorded without 1 H decoupling and both in bulk and in the presence of the gel, using the IPAP sequence [12]. 15 N-Edited nuclear Overhauser spectroscopy (NOESY) were run as described in [13].…”

Section: Methodsmentioning

confidence: 99%

NMR studies of flexible peptides in cavities mimicking the synaptic cleft

et al. 2002

View full text Add to dashboard Cite

show abstract

“…Accordingly, all peptides were studied in a (C2H,),SO/H,0 (90 : 10, by vol.) cryoprotective mixture [39] at 278 K. The spectrum of Tyr-L-Tic-NH, contains the subspectra corresponding to the families of conformations arising from the cisltrans isomerism around the Tyr-L-Tic bond (labelled C and T respectively) and, probably, from the inversion of the L-Tic ring between the two (minimum energy) boat-like conformations (called b+ and b-with reference to the g f or g-value of Ticx,). The relative populations of the two main conformers, Tb+ and Cb+, are 60% and 40%, respectively.…”

Section: Nmr Measurementsmentioning

confidence: 99%

Conversion of Enkephalin and Dermorphin into δ‐Selective Opioid Antagonists by Single‐Residue Substitution

Tancredi¹,

Salvadori

Amodeo

et al. 1994

European Journal of Biochemistry

View full text Add to dashboard Cite

The properties of di-and tri-peptides containing 1,2,3,6tetrahydroisoquinoline-3-carboxylic acid (Tic) in second position suggest that the message domain of opioid peptides can be composed of only two residues [Temussi, P. A., Salvadori, S., Amodeo, P., Guerrini, R., Tomatis, R., Lazarus, L. H., Picone, D. & Tancredi, T. (1994) Biochem. Biophys. Res. Commun. 198,. As a crucial test of the possibility that the Tyr-Tic segment be a message domain in longer peptide sequences, we have inserted it in the sequences of two typical opioid peptides: [Leulenkephalin, a non-selective agonist, and dermorphin, a selective p agonist. Here we report the synthesis and biological activity of [~-Tic'] Abhreviations. (C2H3)2S0, fatty deuterated dimethylsulfoxide; DQF-COSY, double quantum filtered correlation spectroscopy; Fmoc, fluoren-9-ylmethoxycarbonyl; NOESY, nuclear Overhauser effect spectroscopy ; Pen, p,p-dimethylcysteine (penicillamine) ; ROESY, rotating frame Overhauser effect spectroscopy; Tic, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid ; TOCSY, total correlation spectroscopy. MATERIALS AND METHODS Synthesis of peptidesPeptide amides were synthesized by solid-phase methods using fluoren-9-ylmethoxycarbonyl (Fmoc) in the peptide amide linker [5-(4'-Fmoc-aminomethyl-3',5'-dimethoxyphenoxy)-valeric acid] on the poly(ethy1ene glycol)/polystyrene suport (0.18 mmol/g, 0.09 mmol; Millipore. Nu-Fmoc derivatives of amino acids were used in the coupling reactions. The reactive side chains of Tyr and Ser were protected

show abstract

“…The cryoprotective mixtures proposed by Douzou and Petsko [37] are composed of various proportions of water and organic compounds, such as dimethylsulfoxide, dimethylformamide, methanol, ethylene glycol, poly(ethy1ene glycol) or glycerol. In this paper we have extended our original investigation [35,36] of [Leu'lenkephalin in dimethylsulfoxide/water to the mixtures dimethylformamide/water, methanol/water and ethylene glycol/water.…”

Section: Cryoprotective Mixturesmentioning

confidence: 99%

Conformational preferences of [Leu⁵]enkephalin in biomimetic media

Picone

D’Ursi

Motta

et al. 1990

European Journal of Biochemistry

View full text Add to dashboard Cite

The conformation of [Leu'lenkephalin has been studied by 'H-NMR spectroscopy in media more like the actual environment in which the agonist-receptor interaction takes place than water, i.e. in three cryoprotective mixtures (dimethylformamide/water, methanol/water and ethylene glycol/water), in aqueous SDS and in two neat solvents, dimethylformamide and acetonitrile, whose dielectric constants (36.7 and 37.5) are intermediate between that of water and that of the lipid phase. In all cases examined, contrary to the studies in water or dimethylsulfoxide, we were able to detect numerous nuclear Overhauser effects, indicating that the media employed favour welldefined structures and/or reduce the internal motions of the peptide.Data from both organic solvents and cryoprotective mixtures suggest a 4+1 jj' turn as the most probable structure of [Leu'lenkephalin in solution, whereas in SDS/H20 micelles the structural picture appears completely different, suggesting the presence of a 5+2 p turn. The existence of two different preferred conformations of enkephalins may possibly be related to their ability to be effective towards both , u and 6 opioid receptors.The study of the structure activity relationship of opioid peptides has attracted wide interest, both for its practical relevance to the design of new drugs corresponding to the broad pharmacological spectrum of opioid action, and for the theoretical importance of this agonist-receptor interaction [I].In fact, the case of opioid receptors is one of the few in which we can draw on experience with non-peptide ligands [2] (opiates), including many rigid compounds, to identify the main receptor features and to use this information to explain the structure/activity relationship of peptides. However, classical structure/activity relationship studies, based on constitution are arduous, since, in molecules as flexible as small linear peptides, it is very difficult to interpret changes in biological activity as a function of sequential changes without the guideline of a conformational analysis.For historical reasons, the conformation of enkephalins has been investigated more than those of all other natural and synthetic opioid peptides, both in the solid state [3 -111 and in solution [12-281. X-ray diffraction studies have shown that even in the solid state enkephalins can adopt several conformations, ranging from completely extended forms [8 -1 11, imposed by a network of intermolecular hydrogen bonds, to folded forms [3 -71, more or less consistent with the folded structures suggested by theoretical predictions of the bioactive conformation. NMR solution studies [12-281 present an even more complex and, to some extent, contradictory view.Most of the older studies were performed in water or in dimethylsulfoxide, i.e. in media that reproduce conditions typical of transport fluids. These studies favour either a 4-1Correspondence to D. Picone, Dipartimento di Chimica, Universiti di Napoli Federico 11, via Mezzocannone 4, Italy Note. This paper is dedicated to the mcmory of...

show abstract

Proteins at Work: “Stop-Action” Pictures at Subzero Temperatures

Cited by 110 publications

References 99 publications

NMR studies of flexible peptides in cavities mimicking the synaptic cleft

NMR studies of flexible peptides in cavities mimicking the synaptic cleft

Conversion of Enkephalin and Dermorphin into δ‐Selective Opioid Antagonists by Single‐Residue Substitution

Conformational preferences of [Leu⁵]enkephalin in biomimetic media

Contact Info

Product

Resources

About

Proteins at Work: “Stop-Action” Pictures at Subzero Temperatures

Cited by 110 publications

References 99 publications

NMR studies of flexible peptides in cavities mimicking the synaptic cleft

NMR studies of flexible peptides in cavities mimicking the synaptic cleft

Conversion of Enkephalin and Dermorphin into δ‐Selective Opioid Antagonists by Single‐Residue Substitution

Conformational preferences of [Leu5]enkephalin in biomimetic media

Contact Info

Product

Resources

About

Conformational preferences of [Leu⁵]enkephalin in biomimetic media