We found that Hsp31 displays glyoxalase activity that catalyses the conversion of methylglyoxal (MG) to D-lactate without an additional cofactor. The glyoxalase activity was completely abolished in the hchA-deficient strain, confirming the relationship between the hchA gene and its enzymatic activity in vivo. Hsp31 exhibits Michaelis-Menten kinetics for substrates MG with K(m) and k(cat) of Selleck AG-120 1.43 +/-

0.12 mM and 156.9 +/- 5.5 min(-1) respectively. The highest glyoxalase activity was found at 35-40 degrees C and pH of 6.0-8.0, and the activity was significantly inhibited by Cu(2+), Fe(3+) and Zn(2+). Mutagenesis studies based on our evaluation of conserved catalytic residues revealed that the Cys-185 and Glu-77 were essential for catalysis, whereas His-186 was less crucial for enzymatic function, although it participates in the catalytic process. The stationary-phase Escherichia coli cells became more susceptible to MG when hchA was deleted,

which was complemented by an expression of plasmid-encoded hchA. Furthermore, an accumulation of intracellular MG was observed in hchA-deficient strains.”
“Vigilance behaviour is often viewed as a predation avoidance strategy, but animals also use visual monitoring to detect conspecific threats. Studies of social vigilance often consider GSK1838705A cell line how group size or nearby conspecifics influence vigilance levels. Less is known about how more specific social variables, such as relative rank and kinship of a subject’s neighbours, affect vigilance of wild animals along with predation risk. To evaluate alternative functional hypotheses for vigilance behaviour, including predator detection and both extra-and within-group conspecific monitoring, we investigated how predation risk and social factors account for variation in vigilance in wild blue monkeys, Cercopithecus mitis, which show strong aggressive competition between learn more groups and mild aggression within them. Studying 18 adult females in two groups, we measured time spent vigilant in 90 s focal samples, recording the subject’s activity, microhabitat

conditions and identity of neighbours. We used data on dominance ranks and kinship to assess subject-specific social context for each sample. We compared generalized linear mixed models corresponding to each hypothesized function of vigilance, relating variation in vigilance to factors associated with a particular function. The best model related vigilance to predictor variables of all three functions, including recency of an antipredator event, height in canopy, position in forest (edge/interior), recency of an intergroup encounter, number of nearby kin, subject rank and presence of high-ranking neighbours. Overall, most variation in vigilance related to predation risk and between-group competition, while within-group social factors had smaller effects.