Conservation of the conformational dynamics and ligand binding within M49 enzyme family

The hydrogen deuterium exchange (HDX) mass spectrometry combined with molecular dynamics (MD) simulations was employed to investigate conformational dynamics and ligand binding within the M49 family (dipeptidyl peptidase III family). Six dipeptidyl peptidase III (DPP III) orthologues, human, yeast, three bacterial and one plant (moss) were studied. According to the results, all orthologues seem to be quite compact wherein DPP III from the thermophile Caldithrix abyssi seems to be the most compact. The protected regions are located within the two domains core and the overall flexibility profile consistent with semi-closed conformation as the dominant protein form in solution. Besides conservation of conformational dynamics within the M49 family, we also investigated the ligand, pentapeptide tynorphin, binding. By comparing HDX data obtained for unliganded protein with those obtained for its complex with tynorphin it was found that the ligand binding mode is conserved within the family. Tynorphin binds within inter-domain cleft, close to the lower domain β-core and induces its stabilization in all orthologues. Docking combined with MD simulations revealed details of the protein flexibility as well as of the enzyme–ligand interactions.

The hydrogen deuterium exchange (HDX) mass spectrometry combined with molecular dynamics (MD) simulations was employed to investigate conformational dynamics and ligand binding within the M49 family (dipeptidyl peptidase III family).     

In vivo evaluation of fluoride and sodium lauryl sulphate in toothpaste on buccal epithelial cells toxicity

Objectives: The present study addresses the effect of fluoride and sodium lauryl sulphate content of toothpaste on oral epithelial cells in vivo conditions.

Subjects and method: Forty volunteers were assigned into two experimental groups, each of them applying the different brand of toothpaste. Every group has been using three different types of toothpaste (non-fluoride and non-SLS, fluoride and non-SLS, and the fluoride and SLS) of the same brand for 6 months, each for 2 months. The buccal epithelial cells were sampled at baseline and 30, 60, 90, 120, 150 and 180 days after the beginning of the research. Effect on DNA damage was analyzed by micronucleus assay

Results: After 60 days of use, for both tested kinds of toothpaste with fluoride and without SLS, all studied parameters were not significantly different from the results obtained at the time when the participants used a non-fluoride toothpaste. While, after 60 days of use, for one kind of toothpaste with SLS and fluoride, was observed significantly higher incidence of pyknotic cells (2.20?±?0.95, 0.00?±?0.00 vs. 0.05?±?0.22, respectively; p?=?.001), cells with karyorrhexis (2.35?±?1.14, 0.85?±?0.93 vs. 0.40?±?0.68, respectively; p?=?.001), and nuclear buds (1.35?±?0.68, 0.45?±?0.51 vs. 0.45?±?0.60, respectively; p?=?.001), compared to toothpastes of the same brand with fluoride and without SLS, and without fluoride and without SLS, for the same period.

Conclusions: Based on the results, can be concluded that there is no fluorine-dependent cytotoxic or genotoxic effect, while SLS dentifrice increases the number of nuclear morphological changes in buccal epithelial cells.     

Breast vs. bottle: differences in the growth of Croatian infants

The aim of the paper was to compare the growth of rural Croatian infants with 2000 Centers for Disease Control and Prevention (CDC) growth standards and to evaluate the potential preventive influence of breastfeeding on the development of obesity in infancy. Two hundred three infant-mother pairs from Baranja, an Eastern region of Croatia, were enrolled into this study. Retrospective evaluation of infants' medical charts was used to obtain anthropometric data recorded at the birth, 1, 3, 6, 9 and 12 months of age. Infant feeding mode was self-reported by mothers. Breastfed infants gained the least weight of all observed groups. Up to 6 months of age, formula fed infants had the highest weight gain and after 6 months of age, mixed milk fed infants had the highest weight gain. At 12 months of age, 6.4% of all study infants and 7.6% of mixed milk fed infants were at risk of overweight, while the same risk for the group of breastfed infants was 4%. Most of the study infants achieved higher values of body mass and length than the child growth standards. Exclusively breastfed infants, in comparison with other study groups (formula fed infants, mixed milk fed infants and cow's milk fed infants), had lower weight-for-length z-scores during the first year, which suggests that breastfeeding may have a preventive impact on obesity development.     

Oculocerebrorenal syndrome of Lowe protein controls cytoskeletal reorganisation during human platelet spreading

Lowe syndrome (LS) is a rare, X-linked disorder characterised by numerous symptoms affecting the brain, the eyes, and the kidneys. It is caused by mutations in the oculocerebrorenal syndrome of Lowe (OCRL) protein, a 5-phosphatase localised in different cellular compartments that dephosphorylates phosphatidylinositol-4,5-bisphosphate into phosphatidylinositol-4-monophosphate. Some patients with LS also have bleeding disorders, with normal to low platelet (PLT) count and impaired PLT function. However, the mechanism of PLT dysfunction in patients with LS is not completely understood. The main function of PLTs is to activate upon vessel wall injury and stop the bleeding by clot formation. PLT activation is accompanied by a shape change that is a result of massive cytoskeletal rearrangements. Here, we show that OCRL-inhibited human PLTs do not fully spread, form mostly filopodia, and accumulate actin nodules. These nodules co-localise with ARP2/3 subunit p34, vinculin, and sorting nexin 9. Furthermore, OCRL-inhibited PLTs have a retained microtubular coil with high levels of acetylated tubulin. Also, myosin light chain phosphorylation is decreased upon OCRL inhibition, without impaired degranulation or integrin activation. Taken together, these results suggest that OCRL contributes to cytoskeletal rearrangements during PLT activation that could explain mild bleeding problems in patients with LS.