N.M.R. studies of myelin basic protein. VII. Concentration and temperature dependence of amide resonances of the guinea pig encephalitogen in dimethyl sulfoxide

1983 ◽  
Vol 36 (1) ◽  
pp. 33 ◽  
Author(s):  
H Sadikot ◽  
WJ Moore
Keyword(s):  
Magnetic Resonance ◽  
Myelin Basic Protein ◽  
Dimethyl Sulfoxide ◽  
Proton Magnetic Resonance ◽  
Basic Protein ◽  
Chemical Shifts ◽  
Compact Structure ◽  
Temperature Coefficients ◽  
Reverse Turn ◽  
Nuclear Overhauser

The encephalitogenic peptide comprising residues 114-122 in human myelin basic protein, Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Arg, has been studied by proton magnetic resonance at 400 MHz in dimethyl sulfoxide solutions. Temperature coefficients of the chemical shifts of the amide resonances of Glu6, Gly7 and Arg9 have low values indicative of shielding from solvent. These data and nuclear Overhauser enhancements between protons widely separated in the primary structure suggest a compact structure for the peptide in dimethyl sulfoxide, probably associated with a reverse turn about the Gly4Ala5 residues. In freshly prepared solutions in the concentration range 0.20-5.0 mM, effects of intermolecular aggregation are not observed, but such aggregation may occur under other conditions.

Proton magnetic resonance spectra of catechin and bromocatechin derivatives: C6- vs. C8-substitution

1986 ◽  
Vol 64 (10) ◽  
pp. 1998-2005 ◽  
Author(s):  
E. Kiehlmann ◽  
A. S. Tracey
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Nuclear Overhauser Effect ◽  
Chemical Shifts ◽  
Overhauser Effect ◽  
Resonance Frequencies ◽  
The Difference ◽  
Nuclear Overhauser ◽  
Unambiguous Assignment ◽  
Magnetic Resonance Spectra

The 1Hmr spectra of 20 catechin derivatives substituted at C-6/C-8 by bromine and/or hydrogen and at oxygen by methyl, acetyl, and/or hydrogen have been analyzed in deuterated acetone, acetonitrile, and chloroform. Because of its dependence on the nature of the solvent and of the oxygen substituent, the difference between H-6 and H-8 chemical shifts has been found to be an unreliable criterion for the distinction between 8-bromo and 6-bromo isomers. In methylated catechins, double irradiation of H-8 and H-6 enhances one (MeO-7) and two (MeO-5 and MeO-7) methoxy signals, respectively, via the nuclear Overhauser effect. This permits unambiguous assignment of chemical shifts to all ring A protons. The H-6 and H-8 resonance frequencies of catechin have been determined by decoupling of the OH-5 and OH-7 protons.

A nuclear Overhauser effect difference study and a two-dimensional J proton magnetic resonance study of (6S)-prostaglandin I1

1981 ◽  
Vol 59 (10) ◽  
pp. 1449-1454 ◽  
Author(s):  
George Kotovych ◽  
Gerdy H. M. Aarts ◽  
Tom T. Nakashima
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Nuclear Overhauser Effect ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Two Dimensional ◽  
Overhauser Effect ◽  
Effect Difference ◽  
Proton Resonances ◽  
Nuclear Overhauser

High-field nuclear Overhauser effect difference measurements allowed the assignment of the proton resonances for (6S)-prostaglandin I1 in phosphate buffer solutions. The two-dimensional J proton magnetic resonance experiments complemented these studies, as they also allowed the structure of several multiplets to be obtained when these multiplets are hidden by nearby resonances in a normal spectrum. The chemical shifts and coupling constants are compared with the data obtained previously for (6R)-prostaglandin I1.

N.M.R. studies of myelin basic protein. V. 1H N.M.R. of the peptides encephalitogenic in guinea pig

1981 ◽  
Vol 34 (7) ◽  
pp. 1373 ◽  
Author(s):  
SA Margetson ◽  
WJ Moore ◽  
WA Gibbons
Keyword(s):  
Myelin Basic Protein ◽  
Ring Current ◽  
Basic Protein ◽  
Chemical Shifts ◽  
C Terminus ◽  
Proton Resonances ◽  
Nuclear Overhauser ◽  
Nuclear Overhauser Effects ◽  
Peptide Data ◽  
Made In

The 1H n.m.r. spectra of the following peptides have been investigated: (1) the encephalitogenic H-Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys-OH comprising residues 114-122 of bovine myelin basic protein, (2) the corresponding -Arg-OH peptide of human basic protein, (3) the inactive peptide in which D-Ala5 replaces L-Ala5. Measurements were made in D2O solutions at 270 and 600 MHz over a range of temperatures, concentrations and pH. All the proton resonances have been assigned by comparisons with other peptide data, titration shifts, selective decoupling and nuclear Overhauser effects, and data on the (α,α- 2H2)Gly7 nonapeptide. Ring current shifts and their temperature dependence indicated that there is preferential stacking of the Phe and Trp rings, and also interactions between these rings and the Gln and Lys residues near the C-terminus of the peptide. These data suggest a reverse turn at the Gly4-Ala5 residues, a conformation that would be consistent with results from energy calculations and biological activity. The n.m.r. spectra of the L-Ala and D-Ala peptides differed in the temperature coefficients of certain chemical shifts, including particularly those subject to ring current effects. Data in dimethyl sulfoxide were limited by effects of aggregation, but definite conformation differences compared to aqueous solutions were indicated.

Proton magnetic resonance studies at 220 MHz of alanine transfer RNA

1969 ◽  
Vol 47 (4) ◽  
pp. 480-484 ◽  
Author(s):  
Ian C. P. Smith ◽  
Tetsuo Yamane ◽  
R. G. Shulman
Keyword(s):  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Chemical Shifts ◽  
Transfer Rna ◽  
Magnetic Resonance Studies ◽  
The Common ◽  
Line Widths ◽  
Increasing Temperature ◽  
Magnetic Resonance Spectra

Proton magnetic resonance spectra at 220 MHz of alanine transfer RNA do not permit assignments of individual peaks due to each of the common bases; only a peak attributable to protons at position eight in adenine can be assigned with certainty. Measurements of the relative areas of proton magnetic resonance peaks due to the base and ribose-1′ protons indicate that the ribose moieties of tRNA are not involved in bonds stronger than those experienced by the bases. Proton magnetic resonance peaks attributable to the methyl and dihydro protons of the rare bases can be distinguished in the 220 MHz spectra; the variation of their line widths and chemical shifts with increasing temperature indicates that the rare bases are located in regions of the alanine transfer RNA molecule which are more highly organized than indicated by an open cloverleaf model.

Anti-myelin antibodies do not allow earlier diagnosis of multiple sclerosis

2005 ◽  
Vol 11 (4) ◽  
pp. 492-494 ◽  
Author(s):  
E T Lim ◽  
T Berger ◽  
M Reindl ◽  
C M Dalton ◽  
K Fernando ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Optic Neuritis ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Myelin Oligodendrocyte Glycoprotein ◽  
Clinically Isolated Syndrome ◽  
Resonance Imaging

This study investigates whether the presence of serum and plasma anti-myelin oligodendrocyte glycoprotein (MOG) and anti-myelin basic protein (MBP) in patients presenting with a clinically isolated syndrome compatible with demyelination (CIS) predicts early conversion to multiple sclerosis (MS). Forty-seven patients with CIS (46 with optic neuritis) had anti-MOG and anti-MBP antibodies analysed at baseline, and clinical and magnetic resonance imaging assessments. There was no evidence that the MS status based on either the McDonald or Poser criteria relates to the antibody status.

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