Preparation and biological application of antibodies against leucoanthocyanidin reductase and anthocyanidin reductase from grape berry

Proanthocyanidins (PAs) endow wine with the flavor of bitterness and astringency. Both leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) are two key enzymes of PA biosynthesis in grape berries, but the previous studies on these enzymes only focused on the transcriptional expression of these genes. Here, the full-length cDNAs of VvLAR1, VvLAR2 and VvANR, respectively, were cloned from wine grape berries and were then introduced into the pGEX-4T-1 expression vectors, which were highly expressed in Escherichia coli DH5α cells with the induction of the isopropyl-β-D-thiogalactoside (IPTG). The purified fusion proteins were used as the antigens to immunize rabbits, separately. The obtained antiserums were further purified to obtain the immunoglobulin G (Ig G) fractions, which were demonstrated to be capable of specifically immuno-recognizing the VvLAR1, VvLAR2 and VvANR from the crude protein extracts from grape berries with weight masses of approximately 43 kD. The analyses of translational expression of these enzyme genes during berry development and immunohistochemical localization of these proteins, by using the obtained antibodies, showed that a high amount of VvLAR1, VvLAR2 or VvANR was present at the pre-veraison stage and these enzyme proteins were all localized on the outer layer of the berry skin and the vascular bundle, as well as in the inner layer of the seed coat. This work provides an important basis for further studies on PA biosynthesis in grape berries.

Bis[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]manganese(II) trihydrate

In the title complex, [Mn(C11H10N3O2)2]·3H2O, the MnII atom is coordinated by four N atoms and two O atoms in a distorted octa­hedral geometry. The mol­ecules are linked together via hydrogen bonds involving the water molecules. One of these is disordered equally over two positions

Bis[3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]nickel(II) tetra­hydrate

In the title complex, [Ni(C11H9ClN3O2)2]·4H2O, the Ni atom is coordinated by four N atoms and two O atoms derived from two tridentate 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands. The cis-N4O2 donor set defines a distorted octa­hedral geometry. In the crystal structure, the complex and water mol­ecules are linked by O—H⋯O hydrogen bonds

Bis[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato-κ2 N 1,O 2]cadmium(II) 1.75-hydrate

In the title complex, [Cd(C11H10N3O2)2]·1.75H2O, the Cd atom is coordinated by four N atoms and two O atoms from two tridentate 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands in a distorted cis-N4O2 octa­hedral geometry. Three water mol­ecules, with occupancies of 1.0, 0.5 and 0.25, complete the asymmetric unit. The components of the crystal structure are linked via hydrogen bonds, forming a three-dimensional network

[6-(3,5-Dimethyl-1H-pyrazol-1-yl)picolinato](pyridine-2,6-dicarboxyl­ato)copper(II) dihydrate

In the title complex, [Cu(C7H4NO4)(C11H10N3O2)]·2H2O, the CuII atom is in a distorted octa­hedral geometry. The equatorial plane is formed by two N atoms and one O atom from 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate and by one N atom from pyridine-2,6-dicarboxyl­ate (pdc). Two pdc O atoms occupy the axial positions. Water mol­ecules are hydrogen bonded to the complex mol­ecules, forming a two-dimensional sheet structure

Tris[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]gadolinium(III) methanol hemisolvate 2.5-hydrate

In the title complex, [Gd(C11H10N3O2)3]·0.5CH4O·2.5H2O, the Gd atom is coordinated by six N atoms and three O atoms derived from three tridentate monoanionic 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands. The mol­ecules are linked together via hydrogen bonds involving the solvent water and methanol mol­ecules

Aqua­tris[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato]-κ6 N,N′,O;κO-dysprosium(III) trihydrate

In the title complex, [Dy(C11H10N3O2)3(H2O)]·3H2O, the DyIII atom is coordinated by four N atoms and four O atoms derived from three tridentate deprotonated 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands and one water mol­ecule. The complex and solvent water mol­ecules are linked together via O—H⋯O, O—H⋯N, C—H⋯O and C—H⋯π hydrogen-bonding inter­actions, forming a three-dimensional network structure

Binding of PFOS to serum albumin and DNA: insight into the molecular toxicity of perfluorochemicals

<p>Abstract</p> <p>Background</p> <p>Health risk from exposure of perfluorochemicals (PFCs) to wildlife and human has been a subject of great interest for understanding their molecular mechanism of toxicity. Although much work has been done, the toxigenicity of PFCs remains largely unknown. In this work, the non-covalent interactions between perfluorooctane sulfonate (PFOS) and serum albumin (SA) and DNA were investigated under normal physiological conditions, aiming to elucidate the toxigenicity of PFCs.</p> <p>Results</p> <p>In equilibrium dialysis assay, the bindings of PFOS to SA correspond to the Langmuir isothermal model with two-step sequence model. The saturation binding number of PFOS was 45 per molecule of SA and 1 per three base-pairs of DNA, respectively. ITC results showed that all the interactions were spontaneous driven by entropy change. Static quenching of the fluorescence of SA was observed when interacting with PFOS, indicating PFOS bound Trp residue of SA. CD spectra of SA and DNA changed obviously in the presence of PFOS. At normal physiological conditions, 1.2 mmol/l PFOS reduces the binding ratio of Vitamin B₂to SA by more than 30%.</p> <p>Conclusion</p> <p>The ion bond, van der Waals force and hydrophobic interaction contributed to PFOS binding to peptide chain of SA and to the groove bases of DNA duplex. The non-covalent interactions of PFOS with SA and DNA alter their secondary conformations, with the physiological function of SA to transport Vitamin B₂being inhibited consequently. This work provides a useful experimental method for further studying the toxigenicity of PFCs.</p

Diaqua­bis[6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato-κ3 N,N′,O](nitrato-κ2 O,O′)lanthanum(III) monohydrate

In the title complex, [La(C11H10N3O2)2(NO3)(H2O)2]·H2O, the La atom is coordinated by four N atoms and six O atoms derived from two 6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate ligands, one nitrate anion and two water mol­ecules. The mol­ecules are linked together via hydrogen bonds involving the water mol­ecules, forming a three-dimensional network

[3-Chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinato](pyridine-2,6-dicarboxyl­ato)nickel(II) dihydrate

In the title compound, [Ni(C11H9ClN3O2)(C7H3NO4)]·2H2O, the NiII atom is coordinated by two N atoms and one O atom of 3-chloro-6-(3,5-dimethyl-1H-pyrazol-1-yl)picolinate and by one N atom and two O atoms of pyridine-2,6-dicarboxyl­ate in a distorted octa­hedral coordination. In the crystal structure, mol­ecules are linked together by inter­molecular O—H⋯O hydrogen bonds. One water mol­ecule is disordered over two positions; the site occupancies are ca 0.53 and 0.47