Determination of microscopic acid–base parameters from NMR–pH titrations

The theory and practice of proton microspeciation based on NMR–pH titrations are surveyed. Principles of bi-, tri-, tetra-, and n-protic microequilibrium systems are discussed. Evaluation methods are exemplified by case studies on bi- and tetraprotic biomolecules. Selection criteria and properties of ‘reporter’ NMR nuclei are described. Literature data on complete microspeciations of small ligands and site-specific basicity characterizations of peptides and proteins are critically reviewed.

[1]  S. Meiboom,et al.  Application of Nuclear Magnetic Resonance to the Study of Acid‐Base Equilibria , 1957 .

[2]  O. Edholm,et al.  A fast and simple method to calculate protonation states in proteins , 1999, Proteins.

[3]  B. Noszál,et al.  Rota-microspeciation of aspartic acid and asparagine , 1989 .

[4]  P. Driscoll,et al.  Determination of pK(a) values of carboxyl groups in the N-terminal domain of rat CD2: anomalous pK(a) of a glutamate on the ligand-binding surface. , 2000, Biochemistry.

[5]  D. Keire,et al.  Microscopic protonation equilibria and solution conformations of coenzyme A and coenzyme A disulfides , 1992 .

[6]  Robin A. J. Smith,et al.  Synthesis, acidity and 19F NMR characteristics of imidazoles bearing 1-fluorinated substituents with potential application as probes for intracellular pH determination , 1997 .

[7]  M. Goodman,et al.  Variation of nonexchangeable proton resonance chemical shifts as a probe of aberrant base pair formation in DNA. , 1986, Biochemistry.

[8]  C. N. Reilley,et al.  THE DETERMINATION OF PROTON-BINDING SITES BY “NMR TITRATIONS” , 1977 .

[9]  P. D. Newman,et al.  Speciation in aqueous solutions of di-ethylenetriamine-N,N,N′,N″,N″-pentamethylenephosphonic acid and some metal complexes , 1989 .

[10]  C. Ho,et al.  A proton nuclear magnetic resonance investigation of histidyl residues in human normal adult hemoglobin. , 1982, Biochemistry.

[11]  P. Hore.  [3] Solvent suppression , 1989 .

[12]  C. N. Reilley,et al.  Nuclear Magnetic Resonance Studies of Metal Aminopolycarboxylate Complexes. Lability of Individual Metal Ligand Bonds in (Ethylenedinitrilo)-tetraacetate Complexes. , 1964 .

[13]  M. Tanokura,et al.  1H-NMR study on the tautomerism of the imidazole ring of histidine residues. I. Microscopic pK values and molar ratios of tautomers in histidine-containing peptides. , 1983, Biochimica et biophysica acta.

[14]  L. Polgár,et al.  Proton magnetic resonance studies of the states of ionization of histidines in native and modified subtilisins. , 1985, Biochemistry.

[15]  N. Fauconnier,et al.  31P NMR, POTENTIOMETRIC AND SPECTROPHOTOMETRIC STUDIES OF PHYTIC ACID IONIZATION AND COMPLEXATION PROPERTIES TOWARD CO2+, NI2+, CU2+, ZN2+ AND CD2+ , 1999 .

[16]  A. Hill,et al.  The possible effects of the aggregation of the molecules of haemoglobin on its dissociation curves , 1910 .

[17]  M. Tanokura.  1H-NMR study on the tautomerism of the imidazole ring of histidine residues. II. Microenvironments of histidine-12 and histidine-119 of bovine pancreatic ribonuclease A. , 1983, Biochimica et biophysica acta.

[18]  D. Rabenstein,et al.  Determination of microscopic acid dissociation constants by nuclear magnetic resonance spectrometry , 1976 .

[19]  E. Garcı́a-España,et al.  Synthesis and protonation behaviour of the macrocycle 2,6,10,13,17,21-hexaaza[22]metacyclophane. Thermodynamic and NMR studies on the interaction of 2,6,10,13,17,21-hexaaza[22]metacyclophane and on the open-chain polyamine 4,8,11,15-tetraazaoctadecane-1,18-diamine with ATP, ADP and AMP☆ , 1996 .

[20]  S. Mariappan,et al.  Determination of 15N isotope effects on the acid-base equilibria of amino groups in amino acids by carbon-13 NMR , 1993 .

[21]  Federico Fogolari,et al.  Electrostatic properties of bovine β‐lactoglobulin , 2000 .

[22]  D. Lightner,et al.  Synthesis and acidity constants of 13CO2H-labelled dicarboxylic acids. pKas from 13C-NMR , 1996 .

[23]  Silvio Aime,et al.  Synthesis and NMR Studies of Three Pyridine-Containing Triaza Macrocyclic Triacetate Ligands and Their Complexes with Lanthanide Ions. , 1997, Inorganic chemistry.

[24]  G. Schlewer,et al.  MICROSCOPIC ACID-BASE PROPERTIES OF D-MYO-INOSITOL 1,2,6-TRIS(PHOSPHATE) AND ITS 3,4,5-TRIDEOXY ANALOGUE : INFLUENCE OF THE HYDROXY GROUPS OF THE MYO- INOSITOL RING , 1996 .

[25]  M. Gervais,et al.  1D‐ and 2D‐NMR study of a nonapeptide, a fragment of collagen, in its free state and complexed with aluminium (III) , 1987 .

[26]  Michael F. Tweedle,et al.  Synthesis, stability, and structure of gadolinium(III) and yttrium(III) macrocyclic poly(amino carboxylates) , 1994 .

[27]  P. Anelli,et al.  Novel Contrast Agents for Magnetic Resonance Imaging. Synthesis and Characterization of the Ligand BOPTA and Its Ln(III) Complexes (Ln = Gd, La, Lu). X-ray Structure of Disodium (TPS-9-145337286-C-S)-[4-Carboxy-5,8,11-tris(carboxymethyl)-1-phenyl-2-oxa- 5,8,11-triazatridecan-13-oato(5-)]gadolinate(2 , 1995 .

[28]  I. R. Peat,et al.  Determination of the tautomeric form of the imidazole ring of L-histidine in basic solution by carbon-13 magnetic resonance spectroscopy. , 1973, Journal of the American Chemical Society.

[29]  Gerhard Hägele,et al.  The Photo_T-concept: Hard- and Software Combination for the Determination of Macroscopic and Microscopic Dissociation Constants , 1995, Comput. Chem..

[30]  J. Gavilanes,et al.  Characterization of pKa values and titration shifts in the cytotoxic ribonuclease alpha-sarcin by NMR. Relationship between electrostatic interactions, structure, and catalytic function. , 1998, Biochemistry.

[31]  D. Leibfritz,et al.  Sodium binding to and protonation of ATP: a multinuclear magnetic double resonance study at 8.46 tesla. , 1987, Biochimica et biophysica acta.

[32]  A. Allerhand,et al.  Titration behavior of individual tyrosine residues of myoglobins from sperm whale, horse, and red kangaroo. , 1976, The Journal of biological chemistry.

[33]  A. Császár,et al.  Toward direct determination of conformations of protein building units from multidimensional NMR experiments part II: a theoretical case study of formyl-L-valine amide. , 2001, Chemistry.

[34]  J. Feeney,et al.  Carbon-13 NMR protonation shifts of amines, carboxylic acids and amino acids , 1975 .

[35]  M. Casu,et al.  A multinuclear NMR study on the microscopic ionization constants of adenosine-5′-triphosphate in aqueous solution , 1993 .

[36]  B. Potter,et al.  Inframolecular studies of the protonation of adenophostin A: comparison with 1-D-myo-inositol 1,4,5-trisphosphate. , 1999, Biochemical and biophysical research communications.

[37]  S. Snyder,et al.  Characterization of inositol trisphosphate receptor binding in brain. Regulation by pH and calcium. , 1987, The Journal of biological chemistry.

[38]  M. Tanokura.  1H‐Nuclear magnetic resonance study on imidazole–imidazole interaction in L‐histidyl‐L‐histidine and D‐histidyl‐L‐histidine: Analysis including microscopic dissociation series , 1983 .

[39]  Gregory R. Choppin,et al.  Thermodynamics and NMR studies of DTPA-bis(methoxyethylamide) and its derivatives. Protonation and complexation with Ln(III) , 1997 .

[40]  J. Markley,et al.  Correlation proton magnetic resonance studies at 250 MHz of bovine pancreatic ribonuclease. III. Mutual electrostatic interaction between histidine residues 12 and 119. , 1975, Biochemistry.

[41]  P. J. Hore,et al.  Solvent suppression in Fourier transform nuclear magnetic resonance , 1983 .

[42]  P. Bernard,et al.  Inframolecular Protonation Process of myo-Inositol 1,4,5-Tris(phosphate) and Related Compounds: Dynamics of the Intramolecular Interactions and Evidence of C−H···O Hydrogen Bonding , 2000 .

[43]  Craig J. Thalhauser,et al.  Tautomerism, acid‐base equilibria, and H‐bonding of the six histidines in subtilisin BPN′ by NMR , 2003, Protein science : a publication of the Protein Society.

[44]  R. Muller,et al.  Preparation, physico-chemical characterization, and relaxometry studies of various gadolinium(III)-DTPA-bis(amide) derivatives as potential magnetic resonance contrast agents. , 1995, Magnetic resonance imaging.

[45]  W. Horsley,et al.  Carbon-13 magnetic resonance studies of amino acids and peptides. , 1968, Journal of the American Chemical Society.

[46]  M. A. Fabian,et al.  Solvation Effect on Steric Bulk of Ionic Substituents: Imidazolium vs Imidazole , 1994 .

[47]  W. Goddard,et al.  Chelators for radioimmunotherapy: I. NMR and ab initio calculation studies on 1,4,7,10-tetra(carboxyethyl)-1,4,7,10-tetraazacyclododecane (DO4Pr) and 1,4,7-tris(carboxymethyl)-10-(carboxyethyl)-1,4,7,10-tetraazacyclododecane (DO3A1Pr). , 2001, Inorganic chemistry.

[48]  R. Deslauriers,et al.  Carbon-13 nuclear magnetic resonance studies of structure and function in thyrotropin-releasing factor. Determination of the tautomeric form of histidine and relationship to biology activity. , 1974, Biochemistry.

[49]  A. Aubry,et al.  Proton and Metal Ion Interactions with Glycylglycylhistamine, a Serum Albumin Mimicking Pseudopeptide , 1996 .

[50]  D. Walters,et al.  Nuclear magnetic resonance studies of the microscopic protonation of L-cysteine. , 1974, Analytica chimica acta.

[51]  I. R. Peat,et al.  Carbon-13 nuclear magnetic resonance titration shifts in amino acids. , 1974, Journal of the American Chemical Society.

[52]  A. Bianchi,et al.  Proton Coordination by Polyamine Compounds in Aqueous Solution , 1999 .

[53]  B. Noszál.  Group constant: a measure of submolecular basicity , 1986 .

[54]  A. Sherry,et al.  Synthesis, protonation sequence, and NMR studies of polyazamacrocyclic methylenephosphonates , 1989 .

[55]  P E Wright,et al.  Electrostatic calculations of side-chain pK(a) values in myoglobin and comparison with NMR data for histidines. , 1993, Biochemistry.

[56]  S. Aoki,et al.  A new zinc(II) fluorophore 2-(9-anthrylmethylamino)ethyl-appended 1,4,7,10-tetraazacyclododecane. , 2003, Inorganic chemistry.

[57]  B D Sykes,et al.  Chemical shifts as a tool for structure determination. , 1994, Methods in enzymology.

[58]  T. L. Miller,et al.  Carbon-13 magnetic resonance spectra of nucleosides and their Pd(II) complexes. , 1976, Bioinorganic chemistry.

[59]  Cooperativity: a unified view. , 1997, Biochimica et biophysica acta.

[60]  D. Wambeke,et al.  Potentiometric, calorimetric and nuclear magnetic resonance studies of the protonation in aqueous solution of 1-thia-4,7-diazacyclononane-N,N′-diacetic acid, 1-thia-4,8-diazacyclodecane-N,N′-diacetic acid and related open-chain diaminocarboxylic acids , 1992 .

[61]  D. Rabenstein.  Nuclear magnetic resonance studies of the acid-base chemistry of amino acids and peptides. I. Microscopic ionization constants of glutathione and methylmercury-complexed glutathione , 1973 .

[62]  M. Berridge.  Inositol trisphosphate and calcium signalling , 1993, Nature.

[63]  J. Winther,et al.  Why is DsbA such an oxidizing disulfide catalyst? , 1995, Cell.

[64]  B. Noszál,et al.  Microscopic Protonation Equilibria of Oxidized Glutathione , 2003 .

[65]  G. L. Kenyon,et al.  Mechanism of the reaction catalyzed by acetoacetate decarboxylase. Importance of lysine 116 in determining the pKa of active-site lysine 115. , 1996, Biochemistry.

[66]  M. Tanokura,et al.  1H Nuclear magnetic resonance studies of histidine‐containing di‐ and tripeptides. Estimation of the effects of charged groups on the pKa value of the imidazole ring , 1976, Biopolymers.

[67]  H. Rüterjans,et al.  Nuclear magnetic resonance investigation of 15N-labeled histidine in aqueous solution. , 1977, Journal of the American Chemical Society.

[68]  G. Ullmann,et al.  Relations between Protonation Constants and Titration Curves in Polyprotic Acids: A Critical View , 2003 .

[69]  F. Baucke.  Further Insight into the Dissociation Mechanism of Glass Electrodes. The Response in Heavy Water , 1998 .

[70]  A. Sherry,et al.  Nuclear magnetic resonance and potentiometric studies of the protonation scheme of a triaza triacetic macrocycle and its complexes with lanthanum and lutetium , 1985 .

[71]  J. Paschal,et al.  15N nuclear magnetic resonance spectroscopy. The nebramycin aminoglycosides. , 1976, Journal of the American Chemical Society.

[72]  R. Parker,et al.  The interactions between nucleic acids and polyamines. II. Protonation constants and 13C-NMR chemical shift assignments of spermidine, spermine, and homologs. , 1983, Biophysical chemistry.

[73]  J. Prestegard,et al.  Electric field effects in the carbon-13 nuclear magnetic resonance spectra of unsaturated fatty acids. Potential tool for conformational analysis , 1973 .

[74]  E. W. Meijer,et al.  Protonation Mechanism of Poly(propylene imine) Dendrimers and Some Associated Oligo Amines , 1997 .

[75]  E. King.  Acid-base equilibria , 1965 .

[76]  A. D. Buckingham,et al.  CHEMICAL SHIFTS IN THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF MOLECULES CONTAINING POLAR GROUPS , 1960 .

[77]  H. Scheraga,et al.  Structural Studies of Ribonuclease. XXIV. The Application of Nuclear Magnetic Resonance Spectroscopy to Distinguish between the Histidine Residues of Ribonuclease1 , 1966 .

[78]  G. Hägele,et al.  The first automated 470.59 MHz 19F NMR‐controlled titration: dissociation constants and ion‐specific chemical shifts of 2‐amino‐4‐fluoro 2‐methylpent‐4‐enoic acid , 2002 .

[79]  J. Ollig,et al.  NMR-controlled Titrations of Phosphorus Containing Acids and Bases , 1995, Comput. Chem..

[80]  M. D. Sørensen,et al.  Structural details of Asp(B9) human insulin at low pH from two-dimensional NMR titration studies. , 1994, Biochemistry.

[81]  D. Rabenstein,et al.  Determination of the microscopic and macroscopic acid dissociation constants of glycyl-L-histidyl-L-lysine and related histidine peptides. , 1977, Biochemistry.

[82]  Q. Fernaǹdo,et al.  1H NMR and protonation constants of new metal-chelating macrocycles, oxocyclopolyamines with pendant carboxymethyl groups, and the stabilities of their Mg2+ and Ca2+ complexes , 1995 .

[83]  M. D. Joshi,et al.  The pKa of the general acid/base carboxyl group of a glycosidase cycles during catalysis: a 13C-NMR study of bacillus circulans xylanase. , 1996, Biochemistry.

[84]  M. Tweedle,et al.  Effect of Ligand Basicity on the Formation and Dissociation Equilibria and Kinetics of Gd3+ Complexes of Macrocyclic Polyamino Carboxylates , 1994 .

[85]  C. Perrin,et al.  Apparatus for direct addition of reagents into a nuclear magnetic resonance (NMR) sample in the NMR probe , 1999 .

[86]  D. LeMaster.  Structural determinants of the catalytic reactivity of the buried cysteine of Escherichia coli thioredoxin. , 1996, Biochemistry.

[87]  B. Noszál,et al.  Nitrogen-protonation microequilibria and C(2)-deprotonation microkinetics of histidine, histamine, and related compounds , 1991 .

[88]  J. Wieruszeski,et al.  Catechin and epicatechin deprotonation followed by 13C NMR , 2002 .

[89]  D. Rabenstein,et al.  Carbon-13 chemical shift parameters for amines, carboxylic acids, and amino acids , 1976 .

[90]  R. Raines,et al.  Microscopic pKa values of Escherichia coli thioredoxin. , 1997, Biochemistry.

[91]  John D. Roberts,et al.  The Ionization of Citric Acid Studied by the Nuclear Magnetic Resonance Technique , 1960 .

[92]  F. Millett,et al.  Proton magnetic resonance study of the histidines in hemerythrin and chemical identification of the nonligand histidines. , 1980, Biochemistry.

[93]  A. Schechter,et al.  Mathematical models for interacting groups in nuclear magnetic resonance titration curves. , 1972, Biochemistry.

[94]  J. Ward,et al.  Determination of the acid dissociation constants for WR-1065 by proton NMR spectroscopy. , 1992, Radiation research.

[95]  E. Jaffe,et al.  31P nuclear magnetic resonance spectra of the thiophosphate analogues of adenine nucleotides; effects of pH and Mg2+ binding. , 1978, Biochemistry.

[96]  J. Evelhoch,et al.  Dependence of NMR lineshape analysis upon chemical rates and mechanisms: Implications for enzyme histidine titrations , 1980 .

[97]  H. S. Gutowsky,et al.  Dissociation, Chemical Exchange, and the Proton Magnetic Resonance in Some Aqueous Electrolytes , 1953 .

[98]  K. Wiberg,et al.  Physical organic chemistry , 1964 .

[99]  T. Kiss,et al.  Microscopic dissociation processes of some tyrosine derivatives. , 1982, Talanta.

[100]  T. Ishimitsu,et al.  Study of the tautomeric forms of 3,4-dihydroxyphenylacetic acid by carbon-13 nuclear magnetic resonance spectroscopy. , 1979, Talanta.

[101]  William S. Price,et al.  Water Signal Suppression in NMR Spectroscopy , 1999 .

[102]  H. Allen.  Characteristics of azurin from pseudomonas aeruginosa via 270-MHz 1H nuclear magnetic resonance spectroscopy , 1979 .

[103]  Roger A. Jones,et al.  Nitrogen-15-labeled oligodeoxynucleotides. 3. Protonation of the adenine N1 in the A.cntdot.C and A.cntdot.G mispairs of the duplexes {d[CG(15N1)AGAATTCCCG]}2 and {d[CGGGAATTC(15N1)ACG]}2 , 1991 .

[104]  Carver Ja,et al.  Conformational differences between various myoglobin ligated states as monitored by 1H NMR spectroscopy. , 1984 .

[105]  P. Sipos,et al.  Formation microequilibria of proton, calcium and magnesium complexes of the γ-carboxyglutamate ion and related compounds , 1988 .

[106]  P. Braquet,et al.  Ionization constants of ginkgolide B in aqueous solution. , 1996, Analytical chemistry.

[107]  J. Markley.  Nuclear magnetic resonance studies of trypsin inhibitors. Histidines of virgin and modified soybean trypsin inhibitor (Kunitz). , 1973, Biochemistry.

[108]  J. G. Batchelor.  Theory of linear electric field shifts in carbon-13 nuclear magnetic resonance , 1975 .

[109]  Borkovec,et al.  A cluster expansion method for the complete resolution of microscopic ionization equilibria from NMR titrations , 2000, Analytical chemistry.

[110]  D. Case,et al.  A novel view of pH titration in biomolecules. , 2001, Biochemistry.

[111]  H. Kalbitzer,et al.  Proton nuclear magnetic resonance studies on the structure and mechanism of the HPr protein of Staphylococcus aureus , 1981 .

[112]  Michal Borkovec,et al.  Resolution of Microscopic Protonation Mechanisms in Polyprotic Molecules , 2002 .

[113]  K. Berndt,et al.  Structure, dynamics and electrostatics of the active site of glutaredoxin 3 from Escherichia coli: comparison with functionally related proteins. , 2001, Journal of molecular biology.

[114]  A. Martell,et al.  Determination and Use of Stability Constants , 1992 .

[115]  K. Berndt,et al.  Direct NMR observation of the Cys‐14 thiol proton of reduced Escherichia coli glutaredoxin‐3 supports the presence of an active site thiol‐thiolate hydrogen bond , 1999, FEBS letters.

[116]  B. Henry,et al.  pH and pK determinations by high-resolution solid-state 13C NMR: acid-base and tautomeric equilibria of lyophilized L-histidine. , 2002, Journal of the American Chemical Society.

[117]  R. Benesch,et al.  The Acid Strength of the -SH Group in Cysteine and Related Compounds , 1955 .

[118]  J. E. Tackett,et al.  Properties and Infrared Spectra of Ethylenediaminetetraacetic Acid Complexes. IV. Structure of the Ligand in Solution , 1963 .

[119]  D. Rabenstein,et al.  Determination of acid dissociation constants of peptide side-chain functional groups by two-dimensional NMR. , 1997, Analytical chemistry.

[120]  D. Lightner,et al.  Synthesis and acidity constants of 13CO2H-labelled mono and dipyrrole carboxylic acids. pKa from 13C-NMR , 1995 .

[121]  H. Sigel,et al.  Self-association and protonation of adenosine 5'-monophosphate in comparison with its 2'- and 3'-analogues and tubercidin 5'-monophosphate (7-deaza-AMP). , 1987, European journal of biochemistry.

[122]  J. R. Wazer,et al.  Theoretical Interpretation of 31P NMR Chemical Shifts. III. Phosphorus with Five Like Substituents , 1966 .

[123]  W R Baker,et al.  Characterization of the pH titration shifts of ribonuclease A by one- and two-dimensional nuclear magnetic resonance spectroscopy. , 1996, Archives of biochemistry and biophysics.

[124]  C. N. Reilley,et al.  Chemical shifts and protonation shifts in carbon-13 nuclear magnetic resonance studies of aqueous amines , 1975 .

[125]  John D. Roberts,et al.  Nuclear Magnetic Resonance Spectroscopy. ^(13)C Spectra of Aliphatic Carboxylic Acids and Carboxylate Anions , 1969 .

[126]  L. Szilágyi,et al.  Microscopic protonation constants in tobramycin. An NMR and pH study with the aid of partially N-acetylated derivatives. , 1993, Carbohydrate research.

[127]  D. Rabenstein,et al.  Nuclear magnetic resonance studies of the acid–base chemistry of amino acids and peptides. III. Determination of the microscopic and macroscopic acid dissociation constants of α,ω-diaminocarboxylic acids , 1976 .

[128]  J. Shafer,et al.  Determination of a low pK for histidine-159 in the S-methylthio derivative of papain by proton nuclear magnetic resonance spectroscopy. , 1981, Biochemistry.

[129]  D. Kohda,et al.  Characterization of pH titration shifts for all the nonlabile proton resonances a protein by two-dimensional NMR: the case of mouse epidermal growth factor. , 1991, Biochemistry.

[130]  Martin Karplus,et al.  Theory of Carbon NMR Chemical Shifts in Conjugated Molecules , 1963 .

[131]  R. Raines,et al.  His ... Asp catalytic dyad of ribonuclease A: histidine pKa values in the wild-type, D121N, and D121A enzymes. , 1999, Biophysical journal.

[132]  M. Paabo,et al.  Standards for a practical scale of pD in heavy water , 1969 .

[133]  Yoshiaki Oyama,et al.  pKa measurements from nuclear magnetic resonance of tyrosine-150 in class C beta-lactamase. , 2003, The Biochemical journal.

[134]  D. Forsyth,et al.  Intrinsic and equilibrium NMR isotope shift evidence for negative hyperconjugation. , 1986, Journal of the American Chemical Society.

[135]  R. Delgado,et al.  Dissociation constants of Br∅nsted acids in D2O and H2O: studies on polyaza and polyoxa-polyaza macrocycles and a general correlation , 1991 .

[136]  G. C. Levy,et al.  Nitrogen-15 nuclear magnetic resonance spectroscopy , 1979 .

[137]  M. A. Fabian,et al.  Multicomponent NMR titration for simultaneous measurement of relative pKaS. , 1996, Analytical chemistry.

[138]  Bernard Spiess,et al.  Inframolecular acid–base studies of the tris and tetrakis myo-inositol phosphates including the 1,2,3-trisphosphate motif , 2002 .

[139]  R. Kaptein,et al.  Interaction of apocytochrome c and derived polypeptide fragments with sodium dodecyl sulfate micelles monitored by photochemically induced dynamic nuclear polarization 1H NMR and fluorescence spectroscopy. , 1991, Biochemistry.

[140]  C. Larive,et al.  Two‐dimensional 1H NMR spectroscopy of aqueous solutions with elimination of the water resonance by transverse relaxation: Application to assignment of the 1H NMR spectrum of reduced arginine vasopressin , 1991 .

[141]  P. Krogsgaard‐Larsen,et al.  Neuroactive polyamine wasp toxins: nuclear magnetic resonance spectroscopic analysis of the protolytic properties of philanthotoxin-343. , 1996, Journal of medicinal chemistry.

[142]  C. Lecomte,et al.  Conformations and coordination schemes of carboxylate and carbamoyl derivatives of the tetraazamacrocycles cyclen and cyclam, and the relation to their protonation states , 1998 .

[143]  R. B. Nazarski.  Physical Image vs. Structure Relation. Part 3 [1]. Basic Properties and Protonation Mechanism of Some Tetraaza Macrocyclic Ligands , 1999 .

[144]  C. N. Reilley,et al.  Nuclear Magnetic Resonance Studies of Protonation of Polyamine and Aminocarboxylate Compounds in Aqueous Solution. , 1964 .

[145]  C. N. Reilley,et al.  Carbon-13 NMR studies of amino acids: Chemical shifts, protonation shifts, microscopic protonation behavior , 1980 .

[146]  G. Hägele,et al.  NMR-controlled titrations: characterizing aminophosphonates and related structures , 2000 .

[147]  E. G. Rochow,et al.  The Nuclear Magnetic Resonance Absorption of Hydrogen in Methyl Groups. The Electronegativity of Substituents , 1957 .

[148]  J. Markley.  Correlation proton magnetic resonance studies at 250 MHz of bovine pancreatic ribonuclease. I. Reinvestigation of the histidine peak assignments. , 1975, Biochemistry.

[149]  Bernard Spiess,et al.  Complete Resolution of the Microscopic Protonation Equilibria of D-myo-Inositol 1,2,6-Tris(phosphate) and Related Compounds by 31P NMR and Potentiometry , 1995 .

[150]  G. Schlewer,et al.  Inframolecular studies of the protonation of 1d-1,2,4/3,5-cyclopentanepentaol 1,3,4-trisphosphate, a ring-contracted analogue of 1d-myo-inositol 1,4,5-trisphosphate , 1999 .

[151]  S. Linse,et al.  Measurement and modelling of sequence-specific pKa values of lysine residues in calbindin D9k. , 1996, Journal of molecular biology.

[152]  Y. Kyōgoku,et al.  Determination of protonation sites in thermospermine and in some other polyamines by 15N and 13C nuclear magnetic resonance spectroscopy. , 1983, European journal of biochemistry.

[153]  L. Kay,et al.  Measurement of side-chain carboxyl pK(a) values of glutamate and aspartate residues in an unfolded protein by multinuclear NMR spectroscopy. , 2002, Journal of the American Chemical Society.