A close association between the HIV surface protein gp120 and the CD4 T cell receptor initiates the viral multiplication cycle. A 15 amino acid peptide (LAV) within the CD4 binding domain of gp 120 has been shown to retain receptor binding ability. The structural behavior of the LAV peptide has been studied by CD and NMR methods in aqueous solution and upon addition of trifluoroethanol (TFE) to emulate the relatively apolar conditions at the membrane bound receptor. Previous work has shown that the LAV peptide folds into a beta-pleated structure in more polar buffer/TFE mixtures, while a concerted structural change can be observed at a concentration of 60% TFE (v/v). This abrupt, cooperative refolding from a regular beta-sheet to a helical secondary structure is known as "switch" behavior. Former CD experiments with LAV sequence variants have supported the assumption that four amino acids at the N-terminus (LPCR) are indispensable for the "switch." The tetrad has a strong beta-turn forming potential. The suggestion has been formulated that the tetrad can act as a nucleation site governing the refolding. The present NMR study of the LAV peptide in TFE gives evidence for a 3(10)-helix suggesting that the tetrad adopts a type III beta-turn and promotes the formation of a similar bend in the next overlapping tetrad until the sequence is restructured into a 3(10)-helix at a critical polarity favoring intrachain hydrogen bonds.
Measurement of protein unfolding/refolding kinetics and structural characterization of hidden intermediates by NMR relaxation dispersion [Biophysics and Computational Biology]
Measurement of protein unfolding/refolding kinetics and structural characterization of hidden intermediates by NMR relaxation dispersion
Meinhold, D. W., Wright, P. E....
Date: 2011-05-31
Detailed understanding of protein function and malfunction hinges on the ability to characterize transiently populated states and the transitions between them. Here, we use 15N, , and 13CO NMR R2 relaxation dispersion to investigate spontaneous unfolding and refolding events of native apomyoglobin. Above pH 5.0, dispersion is dominated by processes involving fluctuations of the F-helix region, which...
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Measurement of protein unfolding/refolding kinetics and structural characterization of hidden intermediates by NMR relaxation dispersion.
Measurement of protein unfolding/refolding kinetics and structural characterization of hidden intermediates by NMR relaxation dispersion.
Measurement of protein unfolding/refolding kinetics and structural characterization of hidden intermediates by NMR relaxation dispersion.
Proc Natl Acad Sci U S A. 2011 May 11;
Authors: Meinhold DW, Wright PE
Detailed understanding of protein function and malfunction hinges on the ability to characterize transiently populated states and the transitions between them. Here, we use (15)N, , and (13)CO NMR R(2)...
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05-13-2011 02:40 PM
Sequence-Dependent Enrichment of a Model Phosphopeptide: A Combined MALDI-TOF and NMR Study.
Sequence-Dependent Enrichment of a Model Phosphopeptide: A Combined MALDI-TOF and NMR Study.
Sequence-Dependent Enrichment of a Model Phosphopeptide: A Combined MALDI-TOF and NMR Study.
Anal Chem. 2011 Mar 23;
Authors: Lucre?ce M, Emmanuelle S, Fabienne B, Sandrine S, Olivier L, Ge?rard B
The goal of this study was to detect and quantify by MALDI-TOF MS the phosphorylation of a peptide containing the recognition motif of the Protein Kinase C (PKC). Such model peptide can be used as a phosphorylation probe to follow intracellular...
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03-25-2011 06:34 PM
[NMR paper] Redox-dependent 1H NMR spectral features and tertiary structural constraints on the C
Redox-dependent 1H NMR spectral features and tertiary structural constraints on the C-terminal region of putidaredoxin.
Related Articles Redox-dependent 1H NMR spectral features and tertiary structural constraints on the C-terminal region of putidaredoxin.
Biochemistry. 1994 May 31;33(21):6433-41
Authors: Pochapsky TC, Ratnaswamy G, Patera A
Putidaredoxin (Pdx) is a 106-residue Fe2S2 ferredoxin which acts as the physiological reductant and effector of cytochrome P-450cam. Pdx has two accessible oxidation states, Fe+3-Fe+3 (oxidized) and...
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[NMR paper] 19F-NMR study on the pH-dependent regioselectivity and rate of the ortho-hydroxylatio
19F-NMR study on the pH-dependent regioselectivity and rate of the ortho-hydroxylation of 3-fluorophenol by phenol hydroxylase from Trichosporon cutaneum. Implications for the reaction mechanism.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif Related Articles 19F-NMR study on the pH-dependent regioselectivity and rate of the ortho-hydroxylation of 3-fluorophenol by phenol hydroxylase from Trichosporon cutaneum. Implications for the reaction mechanism.
Eur J Biochem. 1993...
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[NMR paper] 13C magic angle spinning NMR study of the light-induced and temperature-dependent cha
13C magic angle spinning NMR study of the light-induced and temperature-dependent changes in Rhodobacter sphaeroides R26 reaction centers enriched in tyrosine.
Related Articles 13C magic angle spinning NMR study of the light-induced and temperature-dependent changes in Rhodobacter sphaeroides R26 reaction centers enriched in tyrosine.
Biochemistry. 1992 Nov 17;31(45):11038-49
Authors: Fischer MR, de Groot HJ, Raap J, Winkel C, Hoff AJ, Lugtenburg J
Solid-state 13C magic angle spinning (MAS) NMR has been used to investigate...
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[NMR paper] Structural characterization of a 39-residue synthetic peptide containing the two zinc
Structural characterization of a 39-residue synthetic peptide containing the two zinc binding domains from the HIV-1 p7 nucleocapsid protein by CD and NMR spectroscopy.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles Structural characterization of a 39-residue synthetic peptide containing the two zinc binding domains from the HIV-1 p7 nucleocapsid protein by CD and NMR spectroscopy.
FEBS Lett. 1991 Nov 4;292(1-2):25-30
Authors: Omichinski JG, Clore GM, Sakaguchi K, Appella E,...
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[NMR paper] Structural characterization of a 39-residue synthetic peptide containing the two zinc
Structural characterization of a 39-residue synthetic peptide containing the two zinc binding domains from the HIV-1 p7 nucleocapsid protein by CD and NMR spectroscopy.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles Structural characterization of a 39-residue synthetic peptide containing the two zinc binding domains from the HIV-1 p7 nucleocapsid protein by CD and NMR spectroscopy.
FEBS Lett. 1991 Nov 4;292(1-2):25-30
Authors: Omichinski JG, Clore GM, Sakaguchi K, Appella E,...
Solvent polarity-dependent structural refolding: a CD and NMR study of a 15 residue p
Linear Mode
