A guanosine 5′-triphosphate-dependent protein kinase is localized in the outer envelope membrane of pea chloroplasts

A guanosine 5-triphosphate (GTP)-dependent protein kinase was detected in preparations of outer chloroplast envelope membranes of pea (Pisum sativum L.) chloroplasts. The protein-kinase activity was capable of phosphorylating several envelope-membrane proteins. The major phosphorylated products were 23- and 32.5-kilo-dalton proteins of the outer envelope membrane. Several other envelope proteins were labeled to a lesser extent. Following acid hydrolysis of the labeled proteins, most of the label was detected as phosphoserine with only minor amounts detected as phosphothreonine. Several criteria were used to distinguish the GTP-dependent protein kinase from an ATP-dependent kinase also present in the outer envelope membrane. The ATP-dependent kinase phosphorylated a very different set of envelope-membrane proteins. Heparin inhibited the GTP-dependent kinase but had little effect upon the ATP-dependent enzyme. The GTP-dependent enzyme accepted phosvitin as an external protein substrate whereas the ATP-dependent enzyme did not. The outer membrane of the chloroplast envelope also contained a phosphotransferase capable of transferring labeled phosphate from [-32P]GTP to ADP to yield (-32P]ATP. Consequently, addition of ADP to a GTP-dependent protein-kinase assay resulted in a switch in the pattern of labeled products from that seen with GTP to that typically seen with ATP

Elite squash players nutrition knowledge and influencing factors

Background There is a reported mismatch between macronutrient consumption and contemporary macronutrient guidelines in elite standard squash players. Suboptimal dietary practices could be due to a lack of nutrition knowledge among players. Subsequently, the purpose of this study was to assess the sports nutrition knowledge of elite squash players through the Nutrition for Sport Knowledge Questionnaire (NSKQ) and provide an indication of whether players require nutrition support to increase their nutrition knowledge. Methods This cross-sectional study assessed the nutrition knowledge of 77 elite squash players via the NSKQ over the period of June 2020 to August 2020. Results Players conveyed average nutrition knowledge with a mean NSKQ score of 48.78 ± 10.06 (56.07% ± 11.56%). There were no significant differences in NSKQ score between male and female players (p = .532). There was found to be a weak positive association between world ranking and NSKQ score (r = .208) and age and NSKQ score (r = .281). Players who had a relevant undergraduate degree (e.g. BSc Sport & Exercise Science) had significantly greater NSKQ score than players with no relevant qualifications (p = .022). Players who consulted a sports nutritionist to obtain their main source of nutrition information were shown to have significantly greater knowledge than those who acquired knowledge from a sports scientist (p = .01) or the internet / social media (p = .007). Conclusions Players should consult with a sports nutritionist to increase their sport nutrition knowledge. Future research should quantify the effectiveness of a nutritional education intervention at increasing nutrition knowledge in players

Dicarboxylic acid transport in Bradyrhizobium japonicum: use of Rhizobium meliloti dct gene(s) to enhance nitrogen fixation.

A recombinant plasmid encoding Rhizobium meliloti sequences involved in dicarboxylic acid transport (plasmid pRK290:4:46) (E. Bolton, B. Higgisson, A. Harrington, and F. O'Gara, Arch. Microbiol. 144:142-146, 1986) was used to study the relationship between dicarboxylic acid transport and nitrogen fixation in Bradyrhizobium japonicum. The expression of the dct sequences on plasmid pRK290:4:46 in B. japonicum CJ1 resulted in increased growth rates in media containing dicarboxylic acids as the sole source of carbon. In addition, strain CJ1(pRK290:4:46) exhibited enhanced succinate uptake activity when grown on dicarboxylic acids under aerobic conditions. Under free-living nitrogen-fixing conditions, strain CJ1(pRK290:4:46) exhibited higher nitrogenase (acetylene reduction) activity compared with that of the wild-type strain. This increase in nitrogenase activity also correlated with an enhanced dicarboxylic acid uptake rate under these microaerobic conditions. The regulation of dicarboxylic acid transport by factors such as metabolic inhibitors and the presence of additional carbon sources was similar in both the wild-type and the engineered strains. The implications of increasing nitrogenase activity through alterations in the dicarboxylic acid transport system are discussed

Northern rail heritage

SIGLELD:83/30748(Northern) / BLDSC - British Library Document Supply CentreGBUnited Kingdo