Influence of growth environment on the phosphoenolpyruvate: Glucose phosphotransferase activities of Escherichia coli and Klebsiella aerogenes: A comparative study

A consistent difference was found between glucose-limited cultures of Escherichia coli and Klebsiella aerogenes strains in the manner which their apparent cellular content of glucose: phosphoenolpyruvate phosphotransferase (glucose-PTS) varied with growth rate. With the former strains, activity increased as a function of growth rate; in the latter it decreased. However, under glucose-sufficient conditions (potassium-or ammonia-limitation) both species behaved similarly; the glucose-PTS activity was lower and bore no obvious relationship to the rate of glucose consumption expressed by the growing culture. These results are discussed in relation to the role of glucose as a regulator of glucose-PTS synthesis, and to the likely contribution which the glucose-PTS makes to the overall rate of glucose uptake, particularly by cells growing in glucose-sufficient environments.Abbreviation Glucose-PTS phosphoenolpyruvate phosphotransferase From May to November 1978 on study leave in the University of Amsterdam     

Effects of ion-pairing on calculations of ionic activities of major ions in freshwater

Ion-pairing has little effect on ionic activity calculations for weakly mineralized natural water (ionic strength < 2 mM). However, for more strongly mineralized freshwaters, corrections for ion-pairing are necessary if highly accurate ionic activities are required.     

Intimate coupling of creatine phosphokinase and myofibrillar adenosinetriphosphatase

ATPase and creatine phosphokinase (CPK) activities of isolated cardiac myofibrils were determined with ³²P γ-labeled ATP alone and with the addition of phosphorylcreatine (PC). With ATP and PC as substrates the label in the inorganic phosphate formed is greatly diluted indicating that the ATP formed by PC through CPK can reach the ATPase active site more readily than labeled ATP from the medium. The tight coupling of the ATPase and CPK activities further strengthens our view that PC serves an important role as high energy carrier between the energy producing sites (mitochondria) and the energy utilizing sites (myofibrils).     

Chemical characterization of a new Japanese variant of carbonic anhydrase I,CA INagasaki 1 (76 Arg→Gln)

A new inherited variant of carbonic anhydrase I (CA I), designated CA I_{Nagasaki 1} (CA I_{NGS 1}), was discovered during a survey of hemolysates from 5852 individuals from the cities of Hiroshima and Nagasaki in Japan. Analysis of the amino acid composition of a tryptic peptide from the CA I_{NGS 1} variant indicated that a glutaminyl residue was substituted for an arginyl residue at position 76. Heat degradation studies showed that the CA I_{NGS 1} variant was less stable than normal CA I. The CO₂ hydrase and esterase activities of the normal and variant carbonic anhydrases I, as well as the relative amounts of the two enzymes in heterozygotes, were similar.This work was supported in part by Contract E(11-1)-1552 with the Energy Research and Development Administration, Washington, D.C. (to J. V. Neel), and by U.S. Public Health Service Grant GM-24681.     

Local cold exposure of Andean Indians during normal and simulated activities.

Thermal resonses of Andean Indians were measured during several customary tasks associated with cold exposure in the highlands of southern Peru. These included surface temperature measurements of women while they washed clothing in the river and similar measurements of men while they constructed a diversion channel in the same river. A third test measured the effects of alcohol consumption on body temperatures during light activity. Women maintained slightly warmer hand than foot temperatures. Men maintained nearly equal hand and foot temperatures during the exposure period. Among male subjects the foot rewarmed at a faster rate than the hand. The results from the field studies compared favorably with results from earlier laboratory exposure tests. Comparisons between the river water exposure tests for males and females showed a consistent pattern where females maintained warmer hand and foot temperatures than males. These findings were in accord with previous laboratory studies among Quechua Indians and with the findings reported for other ethnic groups who experience natural cold stress. Alcohol ingestion appeared to have minimal effect in mitigating cold stress response during light activity. This finding was counter to earlier laboratory tests of resting subjects.     

Ground cover and slope exposure effects on micro- and mesobiota in forest soils

The interrelation of Alpine topography with the micro − and mesobiota is still poorly understood. We investigated the effects of ground cover type and slope exposure on the soil microbial biomass (double-stranded DNA, dsDNA) and abundances (real time PCR, qPCR); hydrolytic enzyme activities; and enchytraeid community structure in top soils (2.5-cm increments depth) in subalpine forests in the Italian Alps. Dominant ground covers were grass, moss, litter and woody debris at the north- and the south-facing slopes. The autochthonous soil microbiota (bacteria, fungi and archaea) was quantified by qPCR in the extracellular (eDNA) and intracellular fraction (iDNA) of the total soil DNA pool. A higher eDNA/iDNA ratio indicative of lower microbial activity was recorded in the deepest layer of the grass plots at the north-facing slope. This can be related to a lower degradation of eDNA and/or to an accumulation of eDNA with increasing depth as a result of leaching. The exposure effect was enzyme-specific and higher activities occurred under woody debris primarily at the south-facing slope. These plots also showed a higher nutrient content and a greater microbial biomass assessed as dsDNA yields. Total microannelid abundance was elevated on north-facing slopes on account of strong acidity indicator species. This was related to soil pH being one unit lower compared to the south-facing slope. The thickness of the organic layer (OL + OF + OH) was elevated at the north-facing slope due to a considerably thicker OH-horizon. The vast majority of microannelids at this slope occurred in the organic layer, while at south exposure they were almost evenly distributed between the organic layer and the mineral soil (A-horizon). Exposure was found to be more determinative for the composition of microannelid assemblages than the ground cover type.     

Bioactive terpenoids from Euonymus verrucosus var. pauciflorus showing NO inhibitory activities

In our continuous search for new nitric oxide (NO) inhibitory compounds as potential anti-inflammatory agents or lead compounds for inflammatory diseases, the chemical constituents of Euonymus verrucosus var. pauciflorus were investigated, leading to the isolation of eleven terpenoids including six new diterpenoids, designated as euonymupenes A–F. The structures were elucidated on the basis of NMR and ECD data analysis. Euonymupenes A, C, and F feature rare labdane-type norditerpenoid skeletons. The NO inhibitory effects were evaluated and all of the isolates were found to inhibit lipopolysaccharide (LPS)-induced NO production in murine microglial BV-2 cells. Western blotting analysis indicated that the most active compound (5) can regulate iNOS (inducible nitric oxide synthase) expression. The further molecular docking studies exhibited the affinities of bioactive compounds with iNOS.     

Contribution of Lithologic and Anthropogenic Factors to Surface Soil Heavy Metals in Western Iran Using Multivariate Geostatistical Analyses

Heavy metals’ origin, accumulation, and distribution in soil have been the focus of much attention by many researchers. The objective of this study was to recognize the sources of heavy metals in surface soils in Hamadan Province in western Iran using multivariate geostatistical techniques. A total of 263 surface (0–10 cm) soil samples and 18 rock samples from major parent materials were collected. Cobalt (Co), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) contents of the samples were determined. Selected soil physical and chemical characteristics were also measured. A multivariate geostatistical analysis was performed to identify the common source of heavy metals. The quantities of Co, Cr, and Ni were found to be associated with parent rocks, corresponding to the first factor termed the “lithologic component.” The second factor was mainly attributed to Cu, which also comprised the first and third factors, indicating a mixed source both from lithologic and anthropogenic inputs. Zn and Pb contents were related to the anthropogenic activities and comprised the third factor. A significant correlation was found between metals from the lithogenic sources and selected soil properties such as soil organic matter, clay, CEC, and carbonate, indicating an interaction among them. Generally, Zn and Pb showed a less significant correlation with soil properties.