Goat milk increases gastric emptying and alters caecal short chain fatty acid profile compared with cow milk in healthy rats

Goat and cow milk share similar protein and lipid content, yet goat milk forms softer curds during stomach digestion.

Computational Strategy Revealing the Structural Determinant of Ligand Selectivity towards Highly Similar Protein Targets

Background: Poor selectivity of drug candidates may lead to toxicity and side effects accounting for as high as 60% failure rate, thus, the selectivity is consistently significant and challenging for drug discovery. Objective: To find highly specific small molecules towards very similar protein targets, multiple strategies are always employed, including (1) To make use of the diverse shape of binding pocket to avoid steric bump; (2) To increase binding affinities for favorite residues; (3) To achieve selectivity through allosteric regulation of target; (4) To stabalize the inactive conformation of protein target and (5) To occupy dual binding pockets of single target. Conclusion: In this review, we summarize computational strategies along with examples of their successful applications in designing selective ligands, with the aim to provide insights into everdiversifying drug development practice and inspire medicinal chemists to utilize computational strategies to avoid potential side effects due to low selectivity of ligands.

A Novel Mechanism for NF-κB-Activation via IκB-Aggregation: Implications for Hepatic Mallory-denk-body Induced Inflammation

ABSTRACTBackground & AimsMallory-Denk-bodies (MDBs) are hepatic protein aggregates associated with inflammation both clinically and in MDB-inducing models. Similar protein aggregation in neurodegenerative diseases also triggers inflammation and NF-κB activation. However, the precise mechanism that links protein aggregation to NFκB-activation and inflammatory response remains unclear.MethodsHerein, we find that treating primary hepatocytes with MDB-inducing agents (N-methylprotoporphyrin, protoporphyrin IX (PPIX), or ZnPPIX) elicited an IκBα-loss with consequent NF-κB activation. We characterized the underlying mechanism in detail using hepatocytes from various knockout mice and MEF cell lines and multiple approaches including immunoblotting, EMSA, RT-PCR, confocal immunofluorescence microscopy, affinity immunoprecipitation, and protein solubility assays. Additionally, we performed rigorous proteomic analyses to identify the proteins aggregating upon PPIX treatment and/or co-aggregating with IκBα.ResultsFour known mechanisms of IκBα-loss were probed and excluded. Immunofluorescence analyses of ZnPPIX-treated cells coupled with 8 M urea/CHAPS-extraction revealed that this IκBα-loss was due to its sequestration along with IκBβ into insoluble aggregates. Through proteomic analyses we identified 47 aggregation-prone proteins that co-aggregate with IκBα through direct interaction or proximity. Of these ZnPPIX-aggregation targets, the nucleoporins Nup153 and Nup358/RanBP2 were identified through RNA-interference, as likely mediators of IκBα-nuclear import.ConclusionWe discovered a novel mechanism of inflammatory NF-κB activation through IκB-sequestration into insoluble aggregates along with interacting aggregation-prone proteins. This mechanism may account for the protein aggregate-induced inflammation observed in MDB-associated liver diseases, thereby identifying novel targets for therapeutic intervention. Because of inherent commonalities this MDB cell model is abona fideprotoporphyric model, making these findings equally relevant to the liver inflammation associated with clinical protoporphyria.Lay SummaryMallory-Denk-bodies (MDBs) are hepatic protein aggregates commonly featured in many liver diseases. MDB-presence is associated with the induction of inflammatory responses both clinically and in all MDB-inducing models. Similar protein aggregation in neurodegenerative diseases is also known to trigger inflammation and NFκB pathway activation via an as yet to be characterized non-canonical mechanism. Herein using a MDB-inducing cell model, we uncovered a novel mechanism for NFκB activation via cytosolic IκB-sequestration into insoluble aggregates. Furthermore, using a proteomic approach, we identified 47 aggregation-prone proteins that interact and co-aggregate with IκBα. This novel mechanism may account for the protein aggregate-induced inflammation observed in liver diseases, thereby identifying novel targets for therapeutic intervention.

One fold, two functions: cytochrome P460 and cytochrome c′-β from the methanotroph Methylococcus capsulatus (Bath)

Structural and spectroscopic characterisation of cytochrome c′-β and cytochrome P460 from M. capsulatus (Bath) reveals highly similar protein folds but very different heme pockets, providing functional insights.

Small Cell Carcinomas of the Uterine Cervix and Lung: Proteomics Reveals Similar Protein Expression Profiles

ObjectiveThe phenotypic and pathological features of small cell cervical carcinoma (SMCC) and small small cell lung cancer (SCLC) are very similar; thus, the chemotherapy regimens used for the rare SMCC have been routinely based on regimens used for common SCLC. We set out to explore the protein expression profile similarities between these 2 cancers to prove that linking their therapeutic regimens is justified, with a secondary aim of finding tumor-specific proteins to use as additional biomarkers for more accurate diagnosis of SMCC, and potentially to use as therapeutic targets.MethodsProtein expression analysis was performed for 3 cases of SMCC and 1 example each of SCLC, mucinous adenocarcinoma of the cervix (MACC), lung mucinous adenocarcinoma (MACL), and squamous cell carcinoma of the cervix (SCC). We used cancer tissue–originated spheroids (CTOS) and isobaric tags for relative and absolute quantitation (iTRAQ)–based comprehensive and quantitative protein expression profile analysis. Expression in corresponding clinical samples was verified by immunohistochemistry.ResultsRather than organ of origin–specific patterns, the SMCC and SCLC samples revealed remarkably similar protein expression profiles—in agreement with their matching tumor pathology phenotypes. Sixteen proteins were expressed at least 2-fold higher in both small cell carcinomas (SMCC and SCLC) than in MACC or SCC. Immunohistochemical analysis confirmed higher expression of creatine kinase B-type in SMCC, compared with MACC and SCC.ConclusionsWe demonstrate a significant overlapping similarity of protein expression profiles of lung and cervical small cell carcinomas despite the significant differences in their organs of origin.

Caenorhabditis elegans paraoxonase-like proteins control the functional expression of DEG/ENaC mechanosensory proteins

Caenorhabditis elegans senses gentle touch via a mechanotransduction channel formed from the DEG/ENaC proteins MEC-4 and MEC-10. An additional protein, the paraoxonase-like protein MEC-6, is essential for transduction, and previous work suggested that MEC-6 was part of the transduction complex. We found that MEC-6 and a similar protein, POML-1, reside primarily in the endoplasmic reticulum and do not colocalize with MEC-4 on the plasma membrane in vivo. As with MEC-6, POML-1 is needed for touch sensitivity, the neurodegeneration caused by the mec-4(d) mutation, and the expression and distribution of MEC-4 in vivo. Both proteins are likely needed for the proper folding or assembly of MEC-4 channels in vivo as measured by FRET. MEC-6 detectably increases the rate of MEC-4 accumulation on the Xenopus oocyte plasma membrane. These results suggest that MEC-6 and POML-1 interact with MEC-4 to facilitate expression and localization of MEC-4 on the cell surface. Thus MEC-6 and POML-1 act more like chaperones for MEC-4 than channel components.