Related ArticlesIonization properties of titratable groups in ribonuclease T1. I. pKa values in the native state determined by two-dimensional heteronuclear NMR spectroscopy.
Eur Biophys J. 2001 Jul;30(3):186-97
Authors: Spitzner N, Löhr F, Pfeiffer S, Koumanov A, Karshikoff A, Rüterjans H
pKa values of amino acid side chains of ribonuclease T1 have been determined from the pH dependence of 13C and 15N resonances. It was possible to derive pKa values of single protonation or deprotonation sites of carboxylate and imidazole groups. Deviations from pKa values of free amino acids could be interpreted with electrostatic interactions of corresponding side chains with the protein environment. In particular, the interaction between H27 and E82 led to an increase of the H27 pKa and a decrease of the E82 pKa. The pKa of E28 at the C-terminal end of the alpha-helix was increased because of the dipolar character of the alpha-helix. D76 did not titrate in the investigated pH range of about 2-9. From the chemical shift value this buried side chain seems to be protonated. The pKa values of side chains in the active site deviate from a normal behaviour. The lower pKa value of E58 may be interpreted with the close proximity of this side chain with positively charged H40 and R77. A novel two-dimensional 1H(13Cdelta)13Cgamma correlation experiment was developed to observe the pH dependence of the chemical shifts of the Cgamma resonances of histidine residues. From the inspection of the Cgamma chemical shift-pH profiles it was possible to determine the predominant tautomeric form for the histidine residues at higher pH values.
Structure, dynamics, and ionization equilibria of the tyrosine residues in Bacillus circulans xylanase
Structure, dynamics, and ionization equilibria of the tyrosine residues in Bacillus circulans xylanase
Abstract We have developed NMR spectroscopic methods to investigate the tyrosines within Bacillus circulans xylanase (BcX). Four slowly exchanging buried tyrosine hydroxyl protons with chemical shifts between 7.5 and 12.5 ppm were found using a long-range 13C-HSQC experiment that exploits the 3JCH coupling between the ring 1Hη and 13Cε nuclei. The NMR signals from these protons were assigned via 13C-tyrosine selective labelling and a suite of scalar and 13C,15N-filtered/edited NOE...
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09-17-2011 10:20 AM
[CNS Yahoo group] Re: Real space R values
Re: Real space R values
Hi, The map for which you'd like to calculate the Real Space R-values is the 2Fo-Fc map (or the equivalent, based on ML calculation). It's this map to which
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12-18-2010 01:31 AM
[NMR paper] Application of difference NOE-pumping NMR technique and cold-spray ionization mass sp
Application of difference NOE-pumping NMR technique and cold-spray ionization mass spectrometry to identify a ligand binding with a protein receptor.
Related Articles Application of difference NOE-pumping NMR technique and cold-spray ionization mass spectrometry to identify a ligand binding with a protein receptor.
Anal Sci. 2004 Oct;20(10):1467-70
Authors: Seki H, Sei Y, Shikii K, Shimotakahara S, Utsumi H, Yamaguchi K, Tashiro M
A difference diffusion-based NMR technique and cold-spray ionization mass spectrometry were employed as a...
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11-24-2010 10:01 PM
[NMR paper] Characterization of pKa values and titration shifts in the cytotoxic ribonuclease alp
Characterization of pKa values and titration shifts in the cytotoxic ribonuclease alpha-sarcin by NMR. Relationship between electrostatic interactions, structure, and catalytic function.
Related Articles Characterization of pKa values and titration shifts in the cytotoxic ribonuclease alpha-sarcin by NMR. Relationship between electrostatic interactions, structure, and catalytic function.
Biochemistry. 1998 Nov 10;37(45):15865-76
Authors: Pérez-Cańadillas JM, Campos-Olivas R, Lacadena J, Martínez del Pozo A, Gavilanes JG, Santoro J, Rico M, Bruix M
...
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11-17-2010 11:15 PM
[NMR paper] Individual ionization constants of all the carboxyl groups in ribonuclease HI from Es
Individual ionization constants of all the carboxyl groups in ribonuclease HI from Escherichia coli determined by NMR.
Related Articles Individual ionization constants of all the carboxyl groups in ribonuclease HI from Escherichia coli determined by NMR.
Biochemistry. 1994 May 3;33(17):5275-84
Authors: Oda Y, Yamazaki T, Nagayama K, Kanaya S, Kuroda Y, Nakamura H
All of the individual carboxyl groups (the side-chain carboxyl groups of Asp and Glu, and the C-terminal alpha-carboxyl group) in Escherichia coli ribonuclease HI, which is an enzyme...
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08-22-2010 03:33 AM
[NMR paper] Individual ionization constants of all the carboxyl groups in ribonuclease HI from Es
Individual ionization constants of all the carboxyl groups in ribonuclease HI from Escherichia coli determined by NMR.
Related Articles Individual ionization constants of all the carboxyl groups in ribonuclease HI from Escherichia coli determined by NMR.
Biochemistry. 1994 May 3;33(17):5275-84
Authors: Oda Y, Yamazaki T, Nagayama K, Kanaya S, Kuroda Y, Nakamura H
All of the individual carboxyl groups (the side-chain carboxyl groups of Asp and Glu, and the C-terminal alpha-carboxyl group) in Escherichia coli ribonuclease HI, which is an enzyme...
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08-22-2010 03:33 AM
[NMR paper] 13C NMR determination of the tautomeric and ionization states of folate in its comple
13C NMR determination of the tautomeric and ionization states of folate in its complexes with Lactobacillus casei dihydrofolate reductase.
Related Articles 13C NMR determination of the tautomeric and ionization states of folate in its complexes with Lactobacillus casei dihydrofolate reductase.
Biochemistry. 1993 Jul 13;32(27):6846-54
Authors: Cheung HT, Birdsall B, Frenkiel TA, Chau DD, Feeney J
13C NMR studies provide a convenient way of obtaining detailed information about tautomeric and ionization states in protein-ligand complexes provided...
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08-22-2010 03:01 AM
A Solid-State (17)O NMR Study of l-Tyrosine in Different Ionization States: Implicati
A Solid-State (17)O NMR Study of l-Tyrosine in Different Ionization States: Implications for Probing Tyrosine Side Chains in Proteins.
Related Articles A Solid-State (17)O NMR Study of l-Tyrosine in Different Ionization States: Implications for Probing Tyrosine Side Chains in Proteins.
J Phys Chem B. 2010 Aug 16;
Authors: Zhu J, Lau JY, Wu G
We report experimental characterization of (17)O quadrupole coupling (QC) and chemical shift (CS) tensors for the phenolic oxygen in three l-tyrosine (l-Tyr) compounds: l-Tyr, l-Tyr.HCl, and Na(2)(l-Tyr)....
Ionization properties of titratable groups in ribonuclease T1. I. pKa values in the n
Linear Mode
