Related ArticlesInvestigating the structure and properties of hydrated hydroxypropyl methylcellulose and egg albumin matrices containing carbamazepine: EPR and NMR study.
Pharm Res. 2000 Oct;17(10):1299-308
Authors: Katzhendler I, Mäder K, Azoury R, Friedman M
PURPOSE: The present study was conducted in order to investigate the correlation between the hydration properties of HPMC and EA matrices, gel microstructure and mobility, crystalline changes occurring in the gel and CBZ release kinetics. The influence of HPMC and EA erosion modes on CBZ release kinetics was interpreted in terms of gel microstructures. METHODS: NMR technique was used to determine the T1 and T2 relaxation rates of water in hydrated matrices. PFGSE NMR technique was employed to determine the SDC of water in the gels. EPR technique was used to determine the rotational correlation time of PCA in the hydrated matrices, gel microviscosity, mobile compartment, alpha, beta, gamma parameters and lorentzian/ gaussian ratio. These parameters are indicative of matrix microstructure. RESULTS: CBZ release mechanism from HPMC and EA matrices was markedly different. This behavior was related to the different structures of the polymer and protein. T2 relaxation studies and SDC measurements by NMR revealed higher chain hydration for HPMC compared to EA. Using the EPR technique it has been shown that the microviscosity and mobile compartment of matrices containing HPMC are lower than matrices containing EA. The microviscosity, mobile compartment and S-parameter values of hydrated matrices containing different EA/CBZ ratios were in correlation with the crystallization properties of CBZ in the gels, matrix erosion properties and CBZ release kinetics from the matrices. CONCLUSIONS: Characterization of matrix structures using EPR and NMR techniques supported our hypothesis concerning the mechanism involved in HPMC-CBZ interaction. EA/CBZ matrix microstructure features, analyzed by NMR and EPR techniques, were in correlation with the crystalline changes occurring in the gel and drug release kinetics.
[NMR paper] Investigating the dynamic properties of the transmembrane segment of phospholamban in
Investigating the dynamic properties of the transmembrane segment of phospholamban incorporated into phospholipid bilayers utilizing 2H and 15N solid-state NMR spectroscopy.
Related Articles Investigating the dynamic properties of the transmembrane segment of phospholamban incorporated into phospholipid bilayers utilizing 2H and 15N solid-state NMR spectroscopy.
Biochemistry. 2004 Nov 9;43(44):13899-909
Authors: Tiburu EK, Karp ES, Dave PC, Damodaran K, Lorigan GA
(2)H and (15)N solid-state NMR spectroscopic techniques were used to investigate...
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11-24-2010 10:03 PM
[NMR paper] Solution 1H NMR study of the active site molecular structure and magnetic properties
Solution 1H NMR study of the active site molecular structure and magnetic properties of the cyanomet complex of the isolated, tetrameric beta-chain from human adult hemoglobin.
Related Articles Solution 1H NMR study of the active site molecular structure and magnetic properties of the cyanomet complex of the isolated, tetrameric beta-chain from human adult hemoglobin.
Biochim Biophys Acta. 2004 Sep 1;1701(1-2):75-87
Authors: Tran AT, Kolczak U, La Mar GN
The solution molecular structure and the electronic and magnetic properties of the heme...
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11-24-2010 10:01 PM
[NMR paper] Investigating structural changes in the lipid bilayer upon insertion of the transmemb
Investigating structural changes in the lipid bilayer upon insertion of the transmembrane domain of the membrane-bound protein phospholamban utilizing 31P and 2H solid-state NMR spectroscopy.
Related Articles Investigating structural changes in the lipid bilayer upon insertion of the transmembrane domain of the membrane-bound protein phospholamban utilizing 31P and 2H solid-state NMR spectroscopy.
Biophys J. 2004 Mar;86(3):1564-73
Authors: Dave PC, Tiburu EK, Damodaran K, Lorigan GA
Phospholamban (PLB) is a 52-amino acid integral membrane...
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11-24-2010 09:25 PM
[NMR paper] Structure and dynamics of hydrated statherin on hydroxyapatite as determined by solid
Structure and dynamics of hydrated statherin on hydroxyapatite as determined by solid-state NMR.
Related Articles Structure and dynamics of hydrated statherin on hydroxyapatite as determined by solid-state NMR.
Biochemistry. 2001 Dec 25;40(51):15451-5
Authors: Long JR, Shaw WJ, Stayton PS, Drobny GP
Proteins directly control the nucleation and growth of biominerals, but the details of molecular recognition at the protein-biomineral interface remain poorly understood. The elucidation of recognition mechanisms at this interface may provide...
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11-19-2010 08:44 PM
[NMR paper] Investigating the conformational coupling between the transmembrane and cytoplasmic d
Investigating the conformational coupling between the transmembrane and cytoplasmic domains of a single-spanning membrane protein. A 1H-NMR study.
Related Articles Investigating the conformational coupling between the transmembrane and cytoplasmic domains of a single-spanning membrane protein. A 1H-NMR study.
FEBS Lett. 2001 Sep 21;505(3):431-5
Authors: Mousson F, Beswick V, Coïc YM, Huynh-Dinh T, Sanson A, Neumann JM
PMP1 is a 38-residue single-spanning membrane protein whose C-terminal cytoplasmic domain, Y25-F38, is highly positively...
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11-19-2010 08:44 PM
[Ryan's blog] From FID to Structure in 30 Minutes? Investigating the CASE Limiting Step
Source: Ryan's blog
From FID to Structure in 30 Minutes? Investigating the CASE Limiting Step
In yesterday's post I pointed you to an article that has become the most accessed article of all time in the Journal of Cheminformatics, co-authored by representatives of ACD/Labs. This article is a very comprehensive outline of the different approaches,...
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08-21-2010 08:57 PM
(2)H NMR study of the water dynamics in hydrated myoglobin.
(2)H NMR study of the water dynamics in hydrated myoglobin.
Related Articles (2)H NMR study of the water dynamics in hydrated myoglobin.
J Phys Chem B. 2010 Aug 12;114(31):10209-16
Authors: Lusceac SA, Vogel M
We use 1D and 2D (2)H NMR to study the temperature-dependent mechanism for the rotational motion of myoglobin hydration water. The results show that isotropic and anisotropic water reorientation is observed at high and low temperatures, respectively, with a continuous crossover in the temperature range of 200-230 K. The anisotropic...
Investigating the structure and properties of hydrated hydroxypropyl methylcellulose
Linear Mode
