Genetic relationships between clinical and non-clinical strains of <Emphasis Type="Italic">Yersinia enterocolitica</Emphasis> biovar 1A as revealed by multilocus enzyme electrophoresis and multilocus restriction typing

Background  

Genetic relationships among 81 strains of Y. enterocolitica biovar 1A isolated from clinical and non-clinical sources were discerned by multilocus enzyme electrophoresis (MLEE) and multilocus restriction typing (MLRT) using six loci each. Such studies may reveal associations between the genotypes of the strains and their sources of isolation.     

Discrete charge carrier transfer sites on proteins? A D.C. conductivity study on ultrathin protein films

D.C. electrical conduction in thin protein films (200 mg/cm2; approximately 2 mu in thickness) of bovine serum albumin and its dinitrophenylated derivatives with different stoichiometric composition was investigated at 17, 20 and 23% relative humidities and at room temperature. Statistically significant decrease in conductivity due to derivatization was observed even at protein-2,4-dinitrophenol stoichiometry as low as 1:2. A charge injection mechanism based upon discrete charge carrier transfer sites could account for the observations. Analogous events may operate in cellular signaling and coding.     

Ecology of Compounding Disturbances: The Effects of Prescribed Burning After Clearcutting

Disturbance regimes in much of the boreal forest have shifted from wildfire to clearcutting over the last century, resulting in concerns for biodiversity. Because the boreal forest has evolved under a natural fire regimes, we hypothesized that application of prescribed burning (PB) after clearcutting would result in plant communities more similar to wildfire than clearcut only. However, because clearcutting + PB involves multiple disturbances in a short interval, we proposed an alternate hypothesis that clearcutting + PB would result in a species composition and trait assemblage that differ from those that develop after a single wildfire or clearcutting event. We determined species composition, diversity, and trait composition of 17 clearcut, 17 clearcut + PB, and 15 wildfire sites of jack pine (Pinus banksiana) dominated forests in northwestern Ontario, Canada 15–37 years after disturbance. Contrary to our primary hypothesis we found that clearcut + PB formed communities different from wildfire and clearcut, the latter two being similar. Clearcut + PB harbored more early successional species associated with seed banking, wind dispersal, deciduous foliage, and alien origin than wildfire or clearcut sites, which showed no specific trait associations. Taxonomic and trait analysis of clearcut + PB sites exhibited effects of compound disturbances, as observed after short-interval fires, supporting our alternate hypothesis. We concluded that PB after clearcutting formed plant communities significantly different from those developed either after clearcutting or wildfire alone. We attribute this community divergence to the compounding effects associated with the addition of prescribed fire to these previously disturbed forests.     

Studies on in vitro synthesis of serum lipoproteins in rats maintained on normal and atherogenic diets: effects of cobalt and manganese supplements at deficient and abundant doses

The effects of Co(II) and Mn (II) supplements at abundant as well as, deficient doses on in vitro synthesis of serum lipoproteins in rats maintained on normal and atherogenic diets were studied. While an adequate oral supplement of Co(II) or iv administration of Mn (II) at very low doses to the experimental rats fed on salt-free stock ration diet produces hyperlipidemic changes in increasing C/P ratio in serum and also the serum LP content. On the other hand, the animals on atherogenic diet supplemented with deficient Co(II) or excess Mn(II) results in a lowering of hyperlipidemia and hyperlipoproteinemia, with concomitant decrease in C/P ratio. Dietary lipids (eg. cholesterol, butter-fat etc.) vis-a-vis Mn (II) deficiency or Co(II) in excess reflect a homeostatic control mechanism for keeping the excess lipid in a state of solution as lipoprotein complexes. Deficient Co(II) or excess Mn (II) in turn, results in a decrease in protein synthesis and a relatively impaired rate of secretion of protein from liver to serum. Moreover, Mn (II) deficiency increases, while its abundance, significantly restricts 14C- labelled amino acid incorporation into alpha 2-lipoprotein molecules. Neither cobalt depletion, nor its adequate oral substitution help improvise the hepatic synthesis of alpha 2-apolipoproteins in experimental animals. This situation remains unaltered even by overloading the diets with saturated fats or by other atherogenic agents, instead of vegetable oils preferably rich in mono or dienoic fatty acids.     

Predicting protein folding rate change upon point mutation using residue‐level coevolutionary information

Change in folding kinetics of globular proteins upon point mutation is crucial to a wide spectrum of biological research, such as protein misfolding, toxicity, and aggregations. Here we seek to address whether residue‐level coevolutionary information of globular proteins can be informative to folding rate changes upon point mutations. Generating residue‐level coevolutionary networks of globular proteins, we analyze three parameters: relative coevolution order (rCEO), network density (ND), and characteristic path length (CPL). A point mutation is considered to be equivalent to a node deletion of this network and respective percentage changes in rCEO, ND, CPL are found linearly correlated (0.84, 0.73, and ?0.61, respectively) with experimental folding rate changes. The three parameters predict the folding rate change upon a point mutation with 0.031, 0.045, and 0.059 standard errors, respectively. Proteins 2016; 84:3–8. © 2015 Wiley Periodicals, Inc.