Understanding the interaction determinants of CAPN1 inhibition by CAST4 from bovines using molecular modeling techniques

Experimental Verification of CAPN1 and CAST Gene Polymorphisms in Different Generations of Da-Heng Broilers

The micromolar calcium activated neutral protease (CAPN1) and calpastatin (CAST) have been widely regarded as genes related to muscle growth and meat tenderness. The objective of this study was to verify the association of SNPs of CAPN1 and CAST genes with carcass and tenderness traits and search the possible change patterns of SNPs in CAPN1 and CAST genes in six generations of broiler breeding process for growth rate, efficiency, and reproduction, during the third generation and the ninth generation, respectively. We found that, for CAPN1, genetic effects between SNPs (G3535A, C7198A) and meat tenderness were similar in different generations, while SNP3 (G7324A) was a novel polymorphism and had significant association with carcass and tenderness traits (P < 0.05) in this study. Furthermore, there was significant association between SNP4 (G9950A) and carcass indexes instead of tenderness traits (P < 0.05) which was consistent in the two generations. Moreover, although SNP6 (G37868A) of CAST had no relevance to carcass traits or tenderness traits in the third generation, it showed significant association with LW and CW in the ninth generation (P < 0.05).

In silico affinity profiling of neuroactive polyphenols for post-traumatic calpain inactivation: a molecular docking and atomistic simulation sensitivity analysis

Calcium-activated nonlysosomal neutral proteases, calpains, are believed to be early mediators of neuronal damage associated with neuron death and axonal degeneration after traumatic neural injuries. In this study, a library of biologically active small molecular weight calpain inhibitors was used for model validation and inhibition site recognition. Subsequently, two natural neuroactive polyphenols, curcumin and quercetin, were tested for their sensitivity and activity towards calpain's proteolytic sequence and compared with the known calpain inhibitors via detailed molecular mechanics (MM), molecular dynamics (MD), and docking simulations. The MM and MD energy profiles (SJA6017 < AK275 < AK295 < PD151746 < quercetin < leupeptin < PD150606 < curcumin < ALLN < ALLM < MDL-28170 < calpeptin) and the docking analysis (AK275 < AK295 < PD151746 < ALLN < PD150606 < curcumin < leupeptin < quercetin < calpeptin < SJA6017 < MDL-28170 < ALLM) demonstrated that polyphenols conferred comparable calpain inhibition profiling. The modeling paradigm used in this study provides the first detailed account of corroboration of enzyme inhibition efficacy of calpain inhibitors and the respective calpain-calpain inhibitor molecular complexes' energetic landscape and in addition stimulates the polyphenol bioactive paradigm for post-SCI intervention with implications reaching to experimental in vitro, in cyto, and in vivo studies.