The aggregation of cytochrome C may be linked to its flexibility during refolding

Large-scale expression of biopharmaceutical proteins in cellular hosts results in production of large insoluble mass aggregates. In order to generate functional product, these aggregates require further processing through refolding with denaturant, a process in itself that can result in aggregation. Using a model folding protein, cytochrome C, we show how an increase in final denaturant concentration decreases the propensity of the protein to aggregate during refolding. Using polarised fluorescence anisotropy, we show how reduced levels of aggregation can be achieved by increasing the period of time the protein remains flexible during refolding, mediated through dilution ratios. This highlights the relationship between the flexibility of a protein and its propensity to aggregate. We attribute this behaviour to the preferential urea-residue interaction, over self-association between molecules

Incremental and Average Control Costs in a Model of Water Quality Trading with Discrete Abatement Units

Discrete abatement, Incremental control cost, Average control cost, Willingness to pay, D61, Q53,

Economic-environmental trade-offs and the conservativeness of the upper partial moment

Probabilistic programming are typically used to model economic-environmental trade-when environmental outcomes are stochastic. Application of available probabilistic programming techniques such as the upper partial moment (UPM) is problematic due to the conservativeness of the estimated the compliance probability. Conservatively estimated trade-offs may result in overregulation of agricultural production practices. Although the conservativeness of the UPM is usually acknowledged by researchers, none of the researchers investigated the size of conservativeness of the UPM. An alternative non-linear trade-off model specification is developed to investigate the conservativeness of the UPM. Meta data from the validated Soil Water Balance (SWB) crop growth simulation model for irrigated maize in South Africa is used to show that the UPM is very conservative in the estimation of the trade-offs comparing to the new method. However, the size of the conservativeness is very situation-specific and varies due to differences in fixed resources, fertilizer application methods and conservativeness measures