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This review summarises the current knowledge of mineral nutrition for penaeid shrimp. It investigates how the aquatic environment and the lifecycle of shrimp affect requirements and the role that minerals play in shrimp health. Methods of supplying minerals via either water or to feed, and novel ways of supplementing minerals within feed, are discussed. The requirements for individual minerals are summarised with recommendations for minimum levels of dietary inclusion for semi‐intensive and intensive commercial shrimp culture presented where data permits. Estimates of dietary requirement remain broad for most minerals for the main shrimp production species (Penaeus vannamei, Penaeus monodon and Penaeus japonicus), with some essential minerals remaining unstudied (Table 2 in Section 5.10). Mineral nutrition will become more important as intensification and diversification of production systems provide new challenges to shrimp aquaculture. [ABSTRACT FROM AUTHOR]

We study the energy landscapes for membrane protein oligomerization using the Associative memory, Water mediated, Structure and Energy Model with an implicit membrane potential (AWSEMmembrane), a coarse-grained molecular dynamics model previously optimized under the assumption that the energy landscapes for folding α-helical membrane protein monomers are funneled once their native topology within the membrane is established. In this study we show that the AWSEMmembrane force field is able to sample near native binding interfaces of several oligomeric systems. By predicting candidate structures using simulated annealing, we further show that degeneracies in predicting structures of membrane protein monomers are generally resolved in the folding of the higher order assemblies as is the case in the assemblies of both nicotinic acetylcholine receptor and V-type Na+-ATPase dimers. The physics of the phenomenon resembles domain swapping, which is consistent with the landscape following the principle of minimal frustration. We revisit also the classic Khorana study of the reconstitution of bacteriorhodopsin from its fragments, which is the close analogue of the early Anfinsen experiment on globular proteins. Here, we show the retinal cofactor likely plays a major role in selecting the final functional assembly. [ABSTRACT FROM AUTHOR]

The objective was to investigate the effects of 500 and 2000 FTU/kg phytase inclusions in maize–based diets with appropriately reduced nutrient specifications in comparison to a positive control diet. Diets were offered to Ross 308 broiler chickens from 7 to 28 days post-hatch and growth performance, nutrient utilisation parameters, sodium, starch and protein (N) digestibility coefficients were obtained in four small intestinal segments and IP 6 phytate degradation coefficients were determined in the gizzard and in four small intestinal segments. The transition from positive control to negative control diets compromised weight gains, FCR and toe ash by 10.3%, 6.57% and 11.5%, respectively. However, 2000 FTU/kg phytase supplementation completely restored these parameters. At 500 FTU/kg phytase significantly increased starch digestibility coefficients by 12.7% (0.879 versus 0.780) in the distal jejunum and by 4.41% (0.947 versus 0.907) in the proximal ileum and significantly increased starch disappearance rates in all four small intestinal segments. Significant increases in protein (N) digestibility and disappearance rates were limited to the proximal ileum where 500 FTU/kg phytase increased protein (N) digestibility coefficients by 6.08% (0.785 versus 0.740). Phytase, at both inclusions, significantly increased the recovery of sodium in the three anterior small intestinal segments. Interestingly, sodium digestibility coefficients were correlated (P = 0.051 − <0.001) with starch and protein (N) digestibility coefficients in all four small intestinal segments. The greatest IP 6 degradation of 95.5% was observed in the gizzard from 2000 FTU/kg phytase. However, surprisingly high gizzard IP 6 degradation rates were observed in both non-phytase supplemented diets. In contrast, phytate degradation was far more pronounced in the negative control than the positive control diet in four small intestinal segments. This phytate degradation may be to the consequence of an up-regulation of endogenous mucosal phytase activity generated by the phosphorus deficient diet coupled with the lower calcium concentration facilitating mucosal phytase activity. Weight gain was correlated with phytate degradation in the gizzard (r = 0.789; P < 0.001) to a more significant extent than in the four small intestinal segments. Consideration is given to the possibility that phytase may be enhancing intestinal uptakes of glucose via Na + -dependent transport systems. [ABSTRACT FROM AUTHOR]

The practice of offering some whole grain to broiler chickens alongside a balancing concentrate is meeting increasing acceptance in certain regions, including Europe, Canada and Australia. Whole-grain feeding (WGF) regimes provide economic advantages by effectively reducing feed costs but, to varying extents, WGF regimes also generate improvements in energy utilisation and feed conversion efficiency. However, the context in which these improvements are best realised has yet to be defined adequately. The outstanding response to WGF is the development of heavier relative gizzard weights; however, the causative factors and biophysical and biochemical consequences of heavier, and presumably more functional, gizzards have not been properly investigated. It follows that heavier gizzards would enhance the initiation of protein digestion by pepsin and hydrochloric acid and facilitate amylase-induced starch digestion in the small intestine by the prior physical disruption of starch granules. However, it appears that improvements realised by WGF in energy utilisation and feed efficiency cannot be attributed entirely to heavier gizzards. One alternative or additional possibility is that WGF may influence starch digestive dynamics and provide more gradually or slowly digestible starch, which would benefit energy utilisation and feed efficiency. However, if this is the case, the genesis of this provision is not clear, although it may be associated with larger grain particle sizes and/or increased episodes of reverse peristalsis, but not retarded gut passage rates. The present paper reviews the essentially positive impacts of WGF on energy utilisation and feed conversion efficiency and considers the contexts in which these responses may be best realised and the possible mechanisms driving better performance under WGF regimes for chicken-meat production. Whole-grain feeding regimes for chicken-meat production provide economic advantages by reducing feed costs while generating improvements in energy utilisation and feed conversion efficiency; however, the genesis of the performance improvements are not defined. The present paper considers the contexts in which these responses may be best realised. Identifying the drivers will enable the most appropriate WGF strategies to be adopted. [ABSTRACT FROM AUTHOR]

Pancreatic K ATP channel trafficking defects underlie congenital hyperinsulinism (CHI) cases unresponsive to the K ATP channel opener diazoxide, the mainstay medical therapy for CHI. Current clinically used K ATP channel inhibitors have been shown to act as pharmacochaperones and restore surface expression of trafficking mutants; however, their therapeutic utility for K ATP trafficking impaired CHI is hindered by high-affinity binding, which limits functional recovery of rescued channels. Recent structural studies of K ATP channels employing cryo-electron microscopy (cryoEM) have revealed a promiscuous pocket where several known K ATP pharmacochaperones bind. The structural knowledge provides a framework for discovering K ATP channel pharmacochaperones with desired reversible inhibitory effects to permit functional recovery of rescued channels. Using an AI-based virtual screening technology AtomNet ® followed by functional validation, we identified a novel compound, termed Aekatperone, which exhibits chaperoning effects on K ATP channel trafficking mutations. Aekatperone reversibly inhibits K ATP channel activity with a half-maximal inhibitory concentration (IC 50 ) ~ 9 μM. Mutant channels rescued to the cell surface by Aekatperone showed functional recovery upon washout of the compound. CryoEM structure of K ATP bound to Aekatperone revealed distinct binding features compared to known high affinity inhibitor pharmacochaperones. Our findings unveil a K ATP pharmacochaperone enabling functional recovery of rescued channels as a promising therapeutic for CHI caused by K ATP trafficking defects., Competing Interests: Competing Interests The authors declare that they have no competing financial or non-financial interests with the contents of this article.