Clinically used RAF inhibitors are ineffective in RAS mutant tumors because they enhance homo- and heterodimerization of RAF kinases, leading to paradoxical activation of ERK signaling. Overcoming enhanced RAF dimerization and the resulting resistance is a challenge for drug design. Combining multiple inhibitors could be more effective, but it is unclear how the best combinations can be chosen. We built a next-generation mechanistic dynamic model to analyze combinations of structurally different RAF inhibitors, which can efficiently suppress MEK/ERK signaling. This rule-based model of the RAS/ERK pathway integrates thermodynamics and kinetics of drug-protein interactions, structural elements, posttranslational modifications, and cell mutational status as model rules to predict RAF inhibitor combinations for inhibiting ERK activity in oncogenic RAS and/or BRAFV600E backgrounds. Predicted synergistic inhibition of ERK signaling was corroborated by experiments in mutant NRAS, HRAS, and BRAFV600E cells, and inhibition of oncogenic RAS signaling was associated with reduced cell proliferation and colony formation.

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3-Hydroxybutyrate, one of the main blood ketone bodies, has been considered as a critical indicator for diagnosis of diabetic ketoacidosis. Biosensors designed for detection of 3-hydroxybutyrate with advantages of precision, easiness and speedy performance have attracted increasing attention. This study attempted to develop a 3-hydroxybutyrate dehydrogenase-based biosensor in which single-walled carbon nanotubes (SWCNT) was used in order to immobilize the cofactor, NAD(+), on the surface of screen-printed electrode. The formation of NAD(+)-SWCNT conjugates was assessed by electrochemistry and electron microscopy. Cyclic voltammetry was used to analyze the performance of this biosensor electrochemically. The considerable shelf life and reliability of the proposed biosensor to analyze real sample was confirmed by this method. The reduction in the over potential of electrochemical oxidation of NADH to -0.15 V can be mentioned as a prominent feature of this biosensor. This biosensor can detect 3-hydroxybutyrate in the linear range of 0.01-0.1 mM with the low detection limit of 0.009 mM. Simultaneous application of screen-printed electrode and SWCNT has made the biosensor distinguished which can open new prospects for detection of other clinically significant metabolites.

Precise detection of 3-hydroxybutyrate (HB) in biological samples is of great importance for management of diabetic patients. In this study, an HB biosensor based on single-walled carbon nanotubes (SWCNTs)-modified screen-printed electrode (SPE) was developed to determine the concentration of HB in serum. The specific detecting enzyme, HB dehydrogenase, was physically immobilised on SWCNTs deposited on the surface of SPEs. The electrochemical measurement of HB that involved cyclic voltammetry was based on the sAgnal produced by j3-nicotinamide adenine dinucleotide (NADH), one of the products of the enzymatic reaction. The application of SWCNT reduced the oxidation potential of NADH to about -0.05 V. Electrochemical measurements showed that the response of this biosensor had relevant good linearity in the range of 0.1-2 mM with a low detection limit of 0.009 mM. Investigation of biosensor response in the presence of interfering molecules verified its specificity. Furthermore, the study of long-term stability demonstrated the acceptable efficiency of this biosensor for about 100 days.

d-Amino acid transaminase plus mutant phenylalanine dehydrogenase offer an effective one-pot system for 100% conversion of dl-amino acids to the l-form.