Effect of Mechanical Vibrations on the lonMutant of Escherichia coliK-12

It was found that, depending on their frequency, mechanical vibrations (MVs) can either stimulate (4 Hz) or inhibit (50 Hz) the growth and the division of the lonmutant of Escherichia coliK-12. Similar effects were observed when the MV-treated nutrient medium was inoculated with untreated mutant cells. MVs enhanced the motility of mutant cells and the fragmentation of filament cells always present in the populations of lonmutants.     

Sequence microheterogeneity of parvalbumin pI 5.0 of pike: a mass spectrometric study

Parvalbumin (PA) is a muscle and neuronal calcium-binding protein, the major fish and frog allergen. Its characteristic feature is the presence of multiple isoforms with significantly different amino acid sequences. Here we show that the major isoform of northern pike muscle PA (pI 5.0, alpha-PA) exhibits microheterogeneity of amino acid sequence. ESI Q-TOF mass-spectrometry (MS) analysis of alpha-PA sample showed the presence of two components with mass difference of 71 Da. Analysis of tryptic and endoproteinase Asp-N digests of alpha-PA by MALDI-TOF MS revealed peptides, corresponding to two different amino acid sequences. The sequence differences between variant proteins are limited to AB-domain and include substitutions K27A and L31K, and an extra Leu residue between K11 and K12. Since the affected residues comprise a cluster on the surface of PA, an involvement of the identified region into target recognition is suggested. The substitutions at positions 27 and 31 are located in the region of previously identified epitopes of parvalbumin relevant for PA-specific IgE and IgG binding, which suggests different immunoactivities of the variants. The found microheterogeneity of PA is suggested to be of importance for physiological adaptation of the propulsive musculature to developmental and/or environmental requirements and may contribute to PA allergenicity.     

Metal-specific structural changes in parvalbumin

Parvalbumin is a small protein of EF-hand family whose main role is considered to be metal buffering. Recent evidences indicate that parvalbumin also fulfills more complicated functions, which may be determined by the diversity in structural changes in response to the binding of different metal cations. In the present work the conformations of α and β isoforms of pike parvalbumin in the Ca(2+)- and Mg(2+)-loaded state were studied by intrinsic fluorescence, circular dichroism and bis-ANS extrinsic fluorescence. We have determined the structural region causing different spectral response on the binding of Mg(2+)- and Ca(2+) ions in pike β-parvalbumin. Our data reveal similarity of the metal-bound forms of α-parvalbumin. In contrast, those of β isoform differ significantly in the tyrosine spectral range. We also discuss the possible physiological consequences of the structural rearrangements accompanied Mg(2+)/Ca(2+) exchange in pike β-parvalbumin.     

Shared interests or sexual conflict? Spousal age gap,women's wellbeing and fertility in rural Tanzania

The marriage of older men to younger women is common across cultures. On one hand, husband-older marriage may serve the interests of both sexes, a conclusion broadly consistent with reported gender differences in mate preferences. On the other hand, men alone may benefit from such marriages at a cost to women if seniority enables men to exert dominance in conflicts of interest. Indeed, in public health large spousal age gaps are generally deemed “pathological”, both as a cause and consequence of gender inequalities harmful to women. We investigate these alternative models of spousal age gap using data from a cross-sectional survey of women in Mwanza, northwestern Tanzania (n = 993). Consistent with the notion that spousal age gaps are a product of sexual conflict, women typically married with a larger age gap than stated ideals. However, adjusting for potential confounds, spousal age gap was not associated with fertility or the risk of divorce. Furthermore, women's mental health and autonomy in household decision-making was higher in husband-older marriages compared to rare cases of same-age or wife-older marriage. Beyond this comparison, the magnitude of spousal age gaps was unrelated to either measure of women's wellbeing among the overwhelming majority of marriages where the husband was older. Together these findings suggest husband-older marriage does not influence marital stability, relatively large spousal age gaps are neither especially costly nor beneficial to women, and that alternative sociodemographic factors are more important in driving variation in women's wellbeing and reproductive success in this context. Our results support neither a model of mutual benefits, nor a pathological conceptualization of spousal age gaps. We conclude by both encouraging evolutionary human scientists to engage more fully with models of sexual conflict in future studies of marriage and mating, and suggesting that public health scholars consider more neutral interpretations of spousal age differences.     

Ligand binding with continuous modification of binding sites

Simultaneous formulation binding and structure modification of the binding site leads to binding process that can be analyzed within the framework of the non-linear theory of dynamic systems. Such an approach allows us to obtain several properties of the binding center: plurality of stationary (stable and unstable) states at binding, recognition of bistable and hysteretic binding modes. It is also shown that adsorption centre deformation leads to a S-shaped adsorption curve.     

The location of the maximum amplitude focus of cortical evoked potential component N200 in subjects solving a maze problem

The dependence of the efficiency of maze problem solution on the “commitment” of the frontal, parietal, temporal, and occipital cortices to the activity was studied. For this purpose, topographic neurophysiological characteristics of component N200 of cortical evoked potentials were determined and used to locate the maximum amplitude focus (MAF). Right-and left-handed subjects of both sexes (50 persons aged 18–23 years) were divided into five groups: (I) women with a low nonverbal IQ, (II) women with a high nonverbal IQ, (III) men with a low nonverbal IQ, (IV) men with a high nonverbal IQ, and (V) left-handed men with a high nonverbal IQ. In subjects from group III, a successful solution of a maze problem was associated with a high activity only in the occipital cortex. In groups II and V, in addition to the strong commitment of the occipital cortex, about the same activity was observed in the frontal cortex. In groups I and IV, and MAF appeared irregularly if at all, which may have accounted for the low efficiency of maze problem solution in these subjects.