Ternary complexes in solution: Complex formation between copper(II), zinc(II), cadmium(II) and ligands of biological importance

1984 ◽  
Vol 115 (6-7) ◽  
pp. 731-738 ◽  
Author(s):  
K. Kumar ◽  
D. Ram Prasad ◽  
P. C. Nigam
Keyword(s):  
Complex Formation ◽  
Ternary Complexes ◽  
Biological Importance

Ternary complexes of N-carboxymethylaminoacetohydroxamic acid

1981 ◽  
Vol 46 (5) ◽  
pp. 1107-1115 ◽  
Author(s):  
Rolf Karlíček ◽  
Miroslav Polášek ◽  
Vladimír Jokl
Keyword(s):  
Complex Formation ◽  
Ternary System ◽  
Binuclear Complex ◽  
Functional Group ◽  
Hydroxamic Acids ◽  
Ternary Complexes ◽  
Hydrogen Ions ◽  
Ligand Structure ◽  
Excess Copper

The formation of N-carboxymethylaminoacetohydroxamic acid complexes in solutions with excess copper(II) or iron(III) ions or both of them was studied. In the presence of Cu(II), the binuclear complex Cu2H-1L+ was identified; in the ternary system, the complex CuFeH-1L+ was found. This complex formation is necessarily associated with the ligand structure >N-CH2.CO-NHOH and with a new property of hydroxamic acids of this type - detachment of two hydrogen ions from one carbohydroxamic functional group.

scholarly journals A Potentiometric Studies of Ternary Complexes of Co(II), Ni(II), Cu(II) and Zn(II) with Ethylenediaamine-N,N,N1,N1-Tetraacetic Acid and Melonic Acid

2018 ◽  
Vol 34 (6) ◽  
pp. 2782-2788
Author(s):  
Sapna Tomar ◽  
Padma Sikarwar
Keyword(s):  
Free Energy ◽  
Ionic Strength ◽  
Complex Formation ◽  
Ternary Complexes ◽  
Potentiometric Studies ◽  
Tetraacetic Acid ◽  
Complex Formation Equilibria ◽  
Formation Equilibria ◽  
Gibb’S Free Energy ◽  
Made In

Potentiometeric investigation on the complex formation equilibria involving Co(II), Ni(II), Cu(II) & Zn(II) with ethylenediaamine-N,N,N1,N1-tetraacetic acid and melonic acid have been made in solution at three different temps viz. (150, 350, 450C). Important thermodynamic parameters namely, change in Gibb’s free energy (DG0), change in enthalpy (DH0) and change in entropy (DS0) and stability constant have been determined potentiometrically at ionic strength of 0.1 M (KNO3).

scholarly journals Binding characteristics of pro-insulin-like growth factor-II from cancer patients: binary and ternary complex formation with IGF binding proteins-1 to -6

2000 ◽  
Vol 165 (2) ◽  
pp. 253-260 ◽  
Author(s):  
JJ Bond ◽  
S Meka ◽  
RC Baxter
Keyword(s):  
Complex Formation ◽  
Ternary Complex ◽  
Binding Proteins ◽  
Ternary Complexes ◽  
Binary Complex ◽  
Igf Binding Proteins ◽  
Ternary Complex Formation ◽  
Binary Complexes ◽  
Igf Binding ◽  
Igfbp 3

Many tumours secrete IGF-II in incompletely processed precursor forms. The ability of these pro-IGF-II forms to complex with the six IGF binding proteins (IGFBPs) is poorly understood. In this study, pro-IGF-II has been extracted from the serum and tumour tissue of two patients with non-islet cell tumour hypoglycaemia. These samples were used to study binary complex formation with IGFBPs-1 to -6 using competitive IGF-II binding assays and ternary complex formation with IGFBP-3 and IGFBP-5. In each case, IGFBPs-1 to -6 showed little difference in their ability to form binary complexes with recombinant IGF-II or tumour-derived pro-IGF-II forms, when the preparations were standardised according to IGF-II immunoreactivity. As previously described, ternary complex formation by acid-labile subunit (ALS) with IGFBP-3 and pro-IGF-II was greatly decreased compared with complex formation with mature IGF-II. In contrast, ALS bound similarly to IGFBP-5 in the presence of pro-IGF-II and mature IGF-II. These studies suggest that pro-IGF-II preferentially forms binary complexes with IGFBPs, and ternary complexes with IGFBP-5, rather than ternary complexes with IGFBP-3 as seen predominantly in normal serum. This may increase the tissue availability of serum pro-IGF-II, allowing its insulin-like potential to be realised.

Studies on the Mixed Ligand Complexes Involving Ligands of Biological Importance (Ni(II)/Zn(II)/Cd(II)-1,10-phenanthroline-2,2′ -bipyridyl-phenylalanine)

1977 ◽  
Vol 32 (4) ◽  
pp. 426-429 ◽  
Author(s):  
G. S. Malik ◽  
S. P. Singh ◽  
J. P. Tandon
Keyword(s):  
Ionic Strength ◽  
Metal Ion ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
Biological Importance

pH-metric studies on the interaction of Ni(II), Zn(II) or Cd(II) with 1,10-phenanthroline (Phen) or 2,2′-bipyridyl (Bipy) in the presence of phenylalanine (Phe) indicate the formation of 1:1:1 mixed ligand chelates and their monohydroxo derivatives. The addition of Phe takes place after the combination of Phen or Bipy with the metal ion is complete. The formation constants of the resulting complexes have been determined at 30 ± 1 °C and ionic strength (µ) = 0.1 KNO3 and the ternary complexes involving Phen are found to be more stable than the corresponding complexes involving Bipy as primary ligand.

scholarly journals Alterations in insulin-like growth factor binding protein-3 proteolysis and complex formation in the arthritic joint

2000 ◽  
Vol 165 (3) ◽  
pp. 545-556 ◽  
Author(s):  
EJ Whellams ◽  
LA Maile ◽  
JK Fernihough ◽  
ME Billingham ◽  
JM Holly
Keyword(s):  
Growth Factor ◽  
Synovial Fluid ◽  
Complex Formation ◽  
Binding Protein ◽  
Disease Process ◽  
Ternary Complexes ◽  
Insulin Like Growth Factor ◽  
Igf System ◽  
Igf I ◽  
Igfbp 3

Increased concentrations of insulin-like growth factor (IGF) system components have previously been observed in rheumatoid arthritis (RA) and osteoarthritis (OA); however, disruption of the IGF axis and the implications for the disease process remain largely unaddressed. This study was undertaken to characterise the IGF binding protein (IGFBP)-3 proteolysis and complex formation systems in synovial fluid and to investigate changes in these systems in arthritic disease, and their impact on the availability of IGF. Western blotting or autoradiography of SDS gels was used to visualise IGFBP-3 or its proteolysis. IGF-I and IGFBP-3 concentrations were determined by radioimmunoassays and acid-labile subunit (ALS) was measured by ELISA. A shift in distribution of IGFBP-3 and IGF-I in RA and OA synovial fluids (RASynF, OASynF) and an associated increase in ALS suggested the presence of 150 kDa ternary complexes. IGFBP-3 proteolysis was decreased in RASynF and OASynF, but was apparent in size-fractionated fluid and resembled serum activity. The presence of serum-like inhibitors of IGFBP-3 proteolysis in RASynF was also demonstrated by the ability of this fluid, and 150 kDa fractions from its size fractionation, to inhibit IGFBP-3 proteolysis in the other synovial fluid. A marked disruption in the IGF system was observed, as considerably more IGF-I was retained in ternary complexes. We also classified the IGFBP-3 proteolysis system in synovial fluid and found it to be disturbed in RASynF and OASynF. These changes may be caused by an increased flux of circulatory proteins into synovial fluid, resulting from an inflammation-induced increase in vascular permeability. The net result in RA and OA would be a decrease in IGF availability in arthritic joints, and therefore loss of a potential anabolic stimulus. This disruption to the IGF axis would influence disease progression in RA and OA.

scholarly journals Characterization of the binding defect in insulin-like growth factor binding protein-3 from pregnancy serum

1993 ◽  
Vol 294 (3) ◽  
pp. 847-852 ◽  
Author(s):  
R C Baxter ◽  
A M Suikkari ◽  
J L Martin
Keyword(s):  
Growth Factor ◽  
Complex Formation ◽  
Ternary Complex ◽  
Binding Protein ◽  
Ternary Complexes ◽  
Insulin Like Growth Factor ◽  
Ternary Complex Formation ◽  
Igf I ◽  
Igf Binding ◽  
Igfbp 3

During pregnancy, insulin-like growth factor (IGF) binding protein-3 (IGFBP-3) undergoes proteolysis, rendering it undetectable by radioligand binding techniques. This study examines the physical and functional defect in pregnancy IGFBP-3. Ternary complex formation has been measured by the binding of the acid-labile subunit of the circulating IGFBP-3 complex, which also requires IGF-I or IGF-II binding. IGF-depleted pregnancy IGFBP-3, prepared by size-exclusion chromatography at low pH, could not form a ternary complex in the presence of [Tyr60]IGF-I or of an IGF-I analogue extensively altered in the A-domain, whereas analogues altered in the C- or D-domains complexed as well as native IGF-I. After purification by immunoaffinity chromatography, non-pregnancy and pregnancy IGFBP-3 formed ternary complexes with IGF-I equally well, although the pregnancy-proteolysed protein appeared degraded to approximately 30 kDa. On analysis by affinity labelling, cross-linked ternary complexes containing non-pregnancy or pregnancy IGFBP-3 were predominantly 135-140 kDa, with an additional complex of 110-115 kDa in the pregnancy preparation. After reverse-phase h.p.l.c., affinity-isolated pregnancy IGFBP-3 was inactive, whereas the protein from non-pregnancy serum retained activity. Thus pregnancy-proteolysed IGFBP-3 is altered in its specificity for IGF analogues, and is more labile than non-pregnancy IGFBP-3, but shows little impairment in normal IGF binding or ternary complex formation.

Potentiometric Studies on Stepwise Mixed Ligand Complex Formation

1970 ◽  
Vol 25 (1) ◽  
pp. 22-26 ◽  
Author(s):  
G. Sharma ◽  
J. P. Tandon
Keyword(s):  
Complex Formation ◽  
Metal Ion ◽  
Mixed Ligand Complex ◽  
Iminodiacetic Acid ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Mixed Ligand ◽  
Molar Ratio ◽  
Ligand Complex ◽  
Secondary Ligand

Stepwise mixed ligand complex formation is observed in the systems containing metal ion, iminodiacetic acid (IMDA) as primary ligand and one of the diamines, such as ethylenediamine (en), 1,2-propanediamine (1,2-pn) and 1,3-propanediamine (1,3-pn) as secondary ligands. Potentionmetric titrations indicate the formation of ternary complexes having a 1:1:1 molar ratio of metal ion to iminodiacetic acid to the secondary ligand. Initially, metal-IMDA (1:1) complex is formed in the lower buffer region prior to the formation of the ternary complex and the addition of the secondary ligand takes place only after the combination with the primary ligand is complete. Formation constants (log KMAB) of the ternary complexes have been calculated and the probable reaction mechanism is suggested. The order of stability in terms of metal ion has been found to be Cu (II) > Ni (II) >Zn (II) >Cd (II) and in terms of secondary ligand as 1,2-pn>en>1,3-pn.

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