Heterologous expression of a papain-like protease inhibitor (SnuCalCpI17) in the E. coli and its mode of inhibition

Construction and functional verification of size-reduced plasmids based on TMP resistance gene dfrB10

IMPORTANCE

Plasmid size is one of the factors affecting transfection efficacy in most of the molecular genetic research studies. One effective approach for reducing plasmid size is to replace relatively large, conventional antibiotic resistance genes with the short-size dfrB10 gene. The successful construct of a series of dfrB10-based tool plasmids and their functional validation, via comparison with original plasmids, suggest that dfrB10 is a potent drug resistance selection marker. The antibiotic trimethoprim offers convenient usage comparable to that of ampicillin or kanamycin. Additionally, fluorescence analysis has demonstrated the compatibility of TMP with protein expression in various host cells. Based on these findings, TMP-dfrB10 could be an alternative choice for future use in molecular genetic research studies that require miniature plasmids to achieve optimal results.

Quantitative Measurements of Pharmacological and Toxicological Activity of Molecules

Toxicity and pharmacological activity scales of molecules, in particular toxicants, xenobiotics, drugs, nutraceuticals, etc., are described by multiples indicators, and the most popular is the median lethal dose (LD50). At the molecular level, reversible inhibition or binding constants provide unique information on the potential activity of molecules. The important problem concerning the meaningfulness of IC50 for irreversible ligands/inhibitors is emphasized. Definitions and principles for determination of these quantitative parameters are briefly introduced in this article. Special attention is devoted to the relationships between these indicators. Finally, different approaches making it possible to link pharmacological and toxicological properties of molecules in terms of molecular interactions (or chemical reactions) with their biological targets are briefly examined. Experimental trends for future high-throughput screening of active molecules are pointed out.