Proton NMR study of effects of synergistic anion and metal ion binding on pH titration of the histidinyl side-chain residues of the half-molecules of ovotransferrin

Biochemistry ◽  
1987 ◽  
Vol 26 (11) ◽  
pp. 3115-3120 ◽  
Author(s):  
Robert C. Woodworth ◽  
N. D. Butcher ◽  
S. A. Brown ◽  
A. Brown-Mason
Keyword(s):  
Metal Ion ◽  
Proton Nmr ◽  
Side Chain ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Ph Titration ◽  
Nmr Study

scholarly journals Metal Ion Binding to Parvalbumin. A Proton NMR Study.

1986 ◽  
Vol 40b ◽  
pp. 6-14 ◽  
Author(s):  
Enzio Ragg ◽  
Adrien Cavé ◽  
Torbjörn Drakenberg ◽  
Curt R. Enzell ◽  
Synnøve Liaaen-Jensen ◽  
...  
Keyword(s):  
Metal Ion ◽  
Proton Nmr ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Nmr Study

scholarly journals Metal Ion-Binding Properties of the Diphosphate Ester Analogue, Methylphosphonylphosphate, in Aqueous Solution

1999 ◽  
Vol 6 (6) ◽  
pp. 321-328 ◽  
Author(s):  
Bin Song ◽  
Jing Zhao ◽  
Fridrich Gregáň ◽  
Nadja Prónayová ◽  
S. Ali A. Sajadi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Minor Role ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Ph Titration ◽  
Role Based ◽  
The Stability ◽  
A Minor ◽  
Complex Stabilities

The stability constants of the 1:1 complexes formed between methylphosphonylphosphate (MePP3-), CH3P(O)2--O-PO32- , and Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+,​ or Cd2+ (M2+) were determined by potentiometric pH titration in aqueous solution (25 C° ; l = 0.1 M, NaNO3 ). Monoprotonated M(H;MePP) complexes play only a minor role. Based on previously established correlations for M2+ -diphosphate monoester complex-stabilities and diphosphate monoester β-group. basicities, it is shown that the M(Mepp)- complexes for Mg2+ and the ions of the second half of the 3d series, including Zn2+ and Cd2+, are on average by about 0.15 log unit more stable than is expected based on the basicity of the terminal phosphate group in MePP3-. In contrast, Ba(Mepp)- and Sr(Mepp)- are slightly less stable, whereas the stability for Ca(Mepp)- is as expected, based on the mentioned correlation. The indicated increased stabilities are explained by an increased basicity of the phosphonyl group compared to that of a phosphoryl one. For the complexes of the alkaline earth ions, especially for Ba2+, it is suggested that outersphere complexation occurs to some extent. However, overall the M(Mepp)- complexes behave rather as expected for a diphosphate monoester ligand.

Metal ion binding to dog osteocalcin studied by proton NMR spectroscopy

Biochemistry ◽  
1993 ◽  
Vol 32 (42) ◽  
pp. 11352-11362 ◽  
Author(s):  
Donna T. Isbell ◽  
Shan Du ◽  
Alan G. Schroering ◽  
Giovanna Colombo ◽  
Judith G. Shelling
Keyword(s):  
Nmr Spectroscopy ◽  
Metal Ion ◽  
Proton Nmr ◽  
Ion Binding ◽  
Proton Nmr Spectroscopy ◽  
Metal Ion Binding

scholarly journals Mineral minimization in nature's alternative teeth

2006 ◽  
Vol 4 (12) ◽  
pp. 19-31 ◽  
Author(s):  
Christopher C Broomell ◽  
Rashda K Khan ◽  
Dana N Moses ◽  
Ali Miserez ◽  
Michael G Pontin ◽  
...  
Keyword(s):  
Metal Ion ◽  
Marine Invertebrates ◽  
Side Chain ◽  
Ion Binding ◽  
Mechanical Support ◽  
Metal Ion Binding ◽  
Organic Composition ◽  
Biochemical Analyses ◽  
Relationship Of ◽  
The Relationship

Contrary to conventional wisdom, mineralization is not the only strategy evolved for the formation of hard, stiff materials. Indeed, the sclerotized mouthparts of marine invertebrates exhibit Young's modulus and hardness approaching 10 and 1 GPa, respectively, with little to no help from mineralization. Based on biochemical analyses, three of these mouthparts, the jaws of glycerid and nereid polychaetes and a squid beak, reveal a largely organic composition dominated by glycine- and histidine-rich proteins. Despite the well-known metal ion binding by the imidazole side-chain of histidine and the suggestion that this interaction provides mechanical support in nereid jaws, there is at present no universal molecular explanation for the relationship of histidine to mechanical properties in these sclerotized structures.

Properties of the Ternary (Dien)Pt(PMEA-N7) Complex Containing Diethylenetriamine (Dien) and the Antiviral 9-[2-(Phosphonomethoxy)ethyl]adenine (PMEA). Synthesis, Biological Screening, Acid-Base Behaviour, and Metal Ion-Binding in Aqueous Solution

2000 ◽  
Vol 55 (12) ◽  
pp. 1141-1152 ◽  
Author(s):  
Gunnar Kampf ◽  
Marc Sven Lüth ◽  
Jens Müller ◽  
Antonín Holý ◽  
Bernhard Lippert ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Metal Ion ◽  
Ion Binding ◽  
Uv Spectrophotometry ◽  
Metal Ion Binding ◽  
Ph Titration ◽  
Complex Species ◽  
Ether Oxygen ◽  
The Stability

The synthesis of (Dien)Pt(PMEA-N7), where Dien = diethylenetriamine and PMEA2- = dianion of 9-[2-(phosphonomethoxy)ethyl]adenine, is described. No useful biological activity could be discovered for this complex which is in contrast to the known antiviral properties of PMEA itself. The acidity constants of the twofold protonated H2[(Dien)Pt(PMEA-N7)]2+ complex were determined (UV spectrophotometry and potentiometric pH titration): The release of the proton from the -P(O)2(OH)- group is only slightly affected by the N7-coordinated (Dien)Pt2+ unit, whereas the acidity of the (N1)H+ site is strongly enhanced. The stability constants of the M[(Dien)Pt(PMEA-N7)]2+ complexes with the metal ions M2+ = Mg2+, Ca2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ were measured by potentiometric pH titrations in aqueous solution at 25 °C and I = 0.1 M (NaNO3). Application of previously determined straightline plots of log KM(R-PO3)M versus KH(R-PO3)H for simple phosph(on)ate ligands, R-PO32- where R represents a non-inhibiting residue without an affinity for metal ions, proves that the primary binding site of the complex-ligand, (Dien)Pt(PMEA-N7), with all the metal ions studied is the phosphonate group; in most instances the expected stability is actually reduced by about 0.4 log units due to the N7-bound (Dien)Pt2+ unit. Only for the Cu[(Dien)Pt(PMEA-N7)]2+ and the Zn[(Dien)Pt(PMEA-N7)]2+ systems the formation of some 5-membered chelates involving the ether oxygen atom of the -CH2-O-CH2-PO32- residue could be detected; the formation degrees are 52 ± 9% and 32 ± 14%, respectively. The metal ion-binding properties of (Dien)Pt(PMEA-N7) differ considerably from those of PMEA2-, yet they are relatively similar to those of pyrimidine-nucleoside 5'-monophosphates. The structures of the various complex species in solution are discussed and compared.

Sign in / Sign up

Export Citation Format

Share Document