Lactoferrin affects the adherence and invasion of Streptococcus dysgalactiae ssp. dysgalactiae in mammary epithelial cells

This research was funded by the Food Institutional Research Measure (Dept. of Agriculture, Food and Fisheries, Ireland) Projects 06RDTMFRC437 and 06RDTMFRC445, the Irish Dairy Research Trust and the Teagasc Retooling Program under the National Development Plan. Christine Beecher was in receipt of a Teagasc Walsh Fellowship.peer-reviewedStreptococcus dysgalactiae ssp. dysgalactiae is an important causative agent of bovine mastitis worldwide. Lactoferrin is an innate immune protein that is associated with many functions including immunomodulatory, antiproliferative, and antimicrobial properties. This study aimed to investigate the interactions between lactoferrin and a clinical bovine mastitis isolate, Strep. dysgalactiae ssp. dysgalactiae DPC5345. Initially a deliberate in vivo bovine intramammary challenge was performed with Strep. dysgalactiae DPC5345. Results demonstrated a significant difference in lactoferrin mRNA levels in milk cells between the control and infused quarters 7 h postinfusion. Milk lactoferrin levels in the Strep. dysgalactiae DPC5345 infused quarters were significantly increased compared with control quarters at 48 h postinfusion. In vitro studies demonstrated that lactoferrin had a bacteriostatic effect on the growth of Strep. dysgalactiae DPC5345 and significantly decreased the ability of the bacteria to internalize into HC-11 mammary epithelial cells. Confocal microscopy images of HC-11 cells exposed to Strep. dysgalactiae and lactoferrin further supported this effect by demonstrating reduced invasion of bacteria to HC-11 cells. The combined data suggest that a bovine immune response to Strep. dysgalactiae infection includes a significant increase in lactoferrin expression in vivo, and based on in vitro data, lactoferrin limits mammary cell invasion of this pathogen by binding to the bacteria and preventing its adherence.Irish Dairy Research TrustTeagasc Walsh Fellowship ProgrammeDepartment of Agriculture, Food and the Marin

Cytotoxic Complexes of Sodium Oleate with β-Lactoglobulin

pre-printA complex of α-lactalbumin and oleic acid has previously been shown to induce apoptosis in cancer cells in a number of in vitro and in vivo trials. This complex is called HAMLET or BAMLET, depending on the origin of α-la (human/bovine alpha-lactalbumin made lethal to tumour cells). In the current study, it was shown that bovine β-lactoglobulin (β-lg), upon binding sodium oleate (NaOle), the salt of oleic acid, also acquires cytotoxicity towards tumour cells (human monocytic cells U937), analogously to HAMLET/BAMLET complexes. The properties of the complex were characterized using FIR spectroscopy, HPLC and SDS-PAGE. It was shown that the level of covalent oligomerization (dimers and trimers) of β-lg increased with increasing the molar ratio of sodium oleate NaOle:β-lg in the preparation procedure. At the same time, increasing the molar ratio of NaOle:β-lg increased the cytotoxicity of the complex. The increase in cytotoxicity appeared to be dependent on the amount of bound NaOle in the complex, but not on the content of multimeric forms of β-lg. The NaOle/β-lg complex also showed similarity with BAMLET in penetrating the cell membrane and co-localizing with the cell nucleus. Furthermore, DNA fragmentation studies suggested that tumour cells (U937) treated with the complex died by apoptosis, as in the case of BAMLET, and healthy cells appeared to be less affected by treatment, as shown with model rat adrenal pheochromocytoma cells PC12. In conclusion, β-lg and NaOle can form complexes with apoptosis-inducing qualities comparable to those of BAMLET.The work was funded by the Irish Dairy Research Trust and The Department of Agriculture (Food Institutional Research Measure – FIRM project 08RDTMFRC650) under the National Development Plan 2007-2013. K. Lišková was funded under the TeagascWalsh Fellowship Scheme

What is the coordination number of copper(II) in metallosupramolecular chemistry?

Analysis of structural and solution data shows a specific stabilisation of copper(II) in ternary complexes containing one 2,2:6`,2``-terpyridine and one 2,2`-bipyridine ligand. This is not a general phenomenon relating to five-coordinate copper(II), but rather a specific consequence of the two ligand donor sets. The consequences of this observation for metallosupramolecular chemistry are discussed

The aryl-phen and phen-phen embraces - new supramolecular motifs

The structure of the complex [Cu(2)(2)][PF6] (2 = 2-(4-methoxyphenyl)-1,10-phenanthroline is reported and a series of common face-to-face pi-stacking motifs in [Cu(phen)(2)](+) (phen = 1,10-phenanthroline or substituted derivative) identified through database mining

Exploring copper(I)-based dye-sensitized solar cells : a complementary experimental and TD-DFT investigation

The structures and properties of the homoleptic copper(I) complexes [Cu(1)(2)][PF6] and [Cu(2)(2)][PF6] (1 = 6,6`-dimethyl-2,2`-bipyridine, 2 = 6,6`-bis2-[4-(N,N`-diphenylamino)phenyl]ethenyl-2,2`-bipyridine) are compared, and a strategy of ligand exchange in solution has been used to prepare eight TiO2 surface-bound heteroleptic complexes incorporating ligands with bpy metal-binding domains and carboxylate or phosphonate anchoring groups. The presence of the extended pi-system in 2 significantly improves dye performance, and the most efficient sensitizers are those with phosphonate or phenyl-4-carboxylate anchoring units; a combination of [Cu(2)(2)](+) with the phosphonate anchoring ligand gives a very promising performance (eta = 2.35% compared to 7.29% for standard dye N719 under the same conditions). The high-energy bands in the electronic absorption spectrum of [Cu(2)(2)](+) which arise from ligand-based transitions dominate the spectrum, whereas that of [Cu(1)(2)](+) exhibits both MLCT and ligand pi* >- pi bands. Both [Cu(1)(2)][PF6] and [Cu(2)(2)][PF6] are redox active; while the former exhibits both copper-centred and ligand-based processes, [Cu(2)(2)][PF6] shows only ligand-based reductions. Results of TD-DFT calculations support these experimental data. They predict an electronic absorption spectrum for [Cu(1)(2)](+) with an MLCT band and high-energy ligand-based transitions, and a spectrum for [Cu(2)(2)](+) comprising transitions involving mainly contributions from orbitals with ligand 2 character. We have assessed the effects of the atomic orbital basis set on the calculated absorption spectrum of [Cu(1)(2)](+) and show that a realistic spectrum is obtained by using a 6-311++G** basis set on all atoms, or 6-311++G** on copper and 6-31G* basis set on all other atoms; a smaller basis set on copper leads to unsatisfactory results. Electronic absorption spectra of six heteroleptic complexes have been predicted using TD-DFT calculations, and the transitions making up the dominant bands analysed in terms of the character of the HOMO-LUMO manifold. The calculational data reveal dominant phosphonate ligand character in the LUMO for the dye found to function most efficiently in practice, and also reveal that the orbital character in the HOMOs of the two most efficient dyes is dominated by the non-anchoring ligand 2, suggesting that ligand 2 enhances the performance of the sensitizer by minimizing back-migration of an electron from the semiconductor to the dye