Colorimetric (near-UV absorption spectroscopy) and calorimetric (isothermal titration calorimetry) methods have been used to quantify the equilibrium thermodynamics of arsenite monomethylarsenite (MMA) coordinating glutathione (GSH) dithiols dimercaptosuccinic acid (DMSA), dihydrolipoic (DHLA), dithiothreitol (DTT). We found that both MMA form moderately stable complexes (β = 106−107) with GSH; forms a particularly 2:3 complex ≈ 1018) biological cofactor DHLA; has somewhat higher affinity...

The thermodynamics of Zn2+ binding to three peptides corresponding naturally occurring Zn-binding sequences in transcription factors have been quantified with isothermal titration calorimetry (ITC). These peptides, the third zinc finger Sp1 (Sp1-3), second myelin factor 1 (MyT1-2), and sequence DNA-binding domain glucocorticoid receptor (GR-2), bind Cys2His2, Cys2HisCys, Cys4 coordination, respectively. Circular dichroism confirms that Sp1-3 MyT1-2 considerable negligible Zn-stabilized...

The butadienediyl-bridged complexes [(η5-C5R5)Fe(dppe)]2(μ-CHCHCHCH) (R = H, Me) and their radical cationic dicationic forms have been prepared characterized by cyclic voltammetry, electronic spectroscopy (UV−vis near-IR), EPR, X-ray crystallography Me). Comparisons with each other the literature [(η5-C5H5)Fe(dppm)]2(μ-CHCHCHCH), [(η5-C5Me5)Fe(dppe)]2(μ-C⋮CC⋮C), [(η5-C5Me5)Fe(dppe)]2(μ-C(OMe)CHCHC(OMe)) allowed for systematic evaluation of several structural variations (C5H5 vs C5Me5, dppm...

Cardiac muscle thin filaments are composed of actin, tropomyosin, and troponin that change conformation in response to Ca2+ binding, triggering contraction. Human cardiac C (cTnC) is the Ca2+-sensing component filament. It contains structural sites (III/IV) bind both Mg2+ a regulatory site (II) has been thought only Ca2+. Binding at this initiates series conformational changes culminate force production. However, mechanisms underpin regulation binding II remain unclear. Here, we have...

Nanoscale assembly is an area of research that has vast implications for molecular design, sensing, nanofabrication, supramolecular chemistry, catalysis, and environmental remediation. Here we show poly(amidoamine) (PAMAM) dendrimers both generations 1 (G1) 4 (G4) can host fullerenol per 2 dendrimer primary amines as evidenced by isothermal titration calorimetry, dynamic light scattering spectrofluorometry. Thermodynamically, the interactions were similarly spontaneous between fullerenols,...

The binding of arsenite (As(III)) and monomethylarsenite (MMAIII) to the DNA-binding domain glucocorticoid receptor (GR-DBD) their competition with two required Zn2+ ions this have been investigated isothermal titration calorimetry (ITC) circular dichroism (CD). thermodynamics indicate that MMAIII, but not arsenite, is able compete one ions. This has confirmed by monitoring MMAIII titrations Zn2GR-DBD CD. Only eliminate Zn-stabilized secondary structure, consistent partial or complete...

Abstract Grb7 is a member of the family proteins, which also includes Grb10 and Grb14. All three proteins have been found to be overexpressed in certain cancers cancer cell lines. In particular, (along with receptor tyrosine kinase erbB2) 20–30% breast cancers. general, growth factor bound (Grb) bind activated membrane‐bound kinases (RTKs; e.g., epidermal receptor, EGFR) through their Src homology 2 (SH2) domains. binds erbB2 (a.k.a. EGFR2) may involved signaling pathways that promote...

Adaptor proteins mediate signal transduction from cell surface receptors to downstream signaling pathways. The Grb7 protein family of adaptor is constituted by Grb7, Grb10, and Grb14. This has been shown be overexpressed in certain cancers cancer lines. Grb7-mediated migration proceed through a focal adhesion kinase (FAK)/Grb7 pathway, although the specific participants have not fully determined. In this study, we report that interacts with Hax-1, cytoskeletal-associated found metastatic...

In previous studies, we showed that the tyrosine phosphorylation state of growth factor receptor-bound protein 7 (Grb7) affects its ability to bind transcription regulator FHL2 and cortactin-interacting protein, human HS-1-associated protein-1. Here, present results describing importance dimerization in Grb7-Src homology 2 (SH2) domain terms structural integrity phosphorylated peptide ligands. A phosphorylation-mimic mutant (Y80E-Grb7-SH2) is largely deficient binds a tyrosine-phosphorylated...

Hybrid receptors designed to recognize both the sulfonate headgroup and fluorous tail of perfluorooctanesulfonate (CF3(CF2)7SO3−, "PFOS") were prepared by coupling fluorinated carboxylic acids onto poly(aminomethyl)benzene scaffolds. Binding PFOS, CF3SO3−, p-TsO−, Cl− was monitored 1H NMR isothermal titration calorimetry (ITC). In chloroform solvent, hydrogen-bonding anions is accompanied downfield shifts in amide NH protons evolution heat. Association constants for 1:1 complexation (Kassoc)...

Previous comparative kinetic isotope effects have inferred an allosteric site for fatty acids and their derivatives that modulates substrate selectivity in 15‐lipoxygenases. Hydrogen–deuterium exchange also previously revealed regionally defined enhanced protein flexibility, centred at helix α2 – a gate to the entrance. Direct evidence binding complete understanding of its mechanism remains elusive. In this study, we examine thermodynamics acid mimic, oleyl sulfate (OS), with monomeric model...

Cardiac troponin C (cTnC) is the critical Ca 2+ ‐sensing component of complex. Binding to cTnC triggers a cascade conformational changes within myofilament that culminate in force production. Hypertrophic cardiomyopathy (HCM)‐associated TNNC1 variants generally induce greater degree and duration binding, which may underly hypertrophic phenotype. Regulation contraction has long been thought occur exclusively through binding site II cTnC. However, work by several groups including ours suggest...

Abstract Grb7 is a member of the family proteins, which also includes Grb10 and Grb14. All three proteins have been found to be overexpressed in certain cancers cancer cell lines. In particular, (along with receptor tyrosine kinase erbB2) 20%–30% breast cancers. binds erbB2 may involved signaling pathways that promote formation metastases inflammatory responses. prior study, we reported solution structure Grb7‐SH2/erbB2 peptide complex. this T 1 , 2 steady‐state NOE measurements were...

Although the Cu(2+)-binding sites of prion protein have been well studied when is fully saturated by Cu(2+), Cu(2+)-loading mechanism just beginning to come into view. Because modes at low and intermediate Cu(2+) occupancy necessarily represent highest-affinity binding modes, these are very likely populated under physiological conditions, it thus essential characterize them in order understand better biological function copper-prion interactions. Besides binding-affinity data, almost no...