Gouda Cheese with Modified Content of β-Casein as a Source of Peptides with ACE- and DPP-IV-Inhibiting Bioactivity: A Study Based on In Silico and In Vitro Protocol

In silico and in vitro methods were used to analyze ACE- and DPP-IV-inhibiting potential of Gouda cheese with a modified content of β-casein. Firstly, the BIOPEP-UWM database was used to predict the presence of ACE and DPP-IV inhibitors in casein sequences. Then, the following Gouda cheeses were produced: with decreased, increased, and normative content of β-casein after 1 and 60 days of ripening each (six variants in total). Finally, determination of the ACE/DPP-IV-inhibitory activity and the identification of peptides in respective Gouda-derived water-soluble extracts were carried out. The identification analyses were supported with in silico calculations, i.e., heatmaps and quantitative parameters. All Gouda variants exhibited comparable ACE inhibition, whereas DPP-IV inhibition was more diversified among the samples. The samples derived from Gouda with the increased content of β-casein (both stages of ripening) had the highest DPP-IV-inhibiting potency compared to the same samples measured for ACE inhibition. Regardless of the results concerning ACE and DPP-IV inhibition among the cheese samples, the heatmap showed that the latter bioactivity was predominant in all Gouda variants, presumably because it was based on the qualitative approach (i.e., peptide presence in the sample). Our heatmap did not include the bioactivity of a single peptide as well as its quantity in the sample. In turn, the quantitative parameters showed that the best sources of ACE/DPP-IV inhibitors were all Gouda-derived extracts obtained after 60 days of the ripening. Although our protocol was efficient in showing some regularities among Gouda cheese variants, in vivo studies are recommended for more extensive investigations of this subject.     

The Causes and Potential Injurious Effects of Elevated Serum Leptin Levels in Chronic Kidney Disease Patients

Leptin is an adipokine that regulates appetite and body mass and has many other pleiotropic functions, including regulating kidney function. Increased evidence shows that chronic kidney disease (CKD) is associated with hyperleptinemia, but the reasons for this phenomenon are not fully understood. In this review, we focused on potential causes of hyperleptinemia in patients with CKD and the effects of elevated serum leptin levels on patient kidney function and cardiovascular risk. The available data indicate that the increased concentration of leptin in the blood of CKD patients may result from both decreased leptin elimination from the circulation by the kidneys (due to renal dysfunction) and increased leptin production by the adipose tissue. The overproduction of leptin by the adipose tissue could result from: (a) hyperinsulinemia; (b) chronic inflammation; and (c) significant lipid disturbances in CKD patients. Elevated leptin in CKD patients may further deteriorate kidney function and lead to increased cardiovascular risk.     

Toward a toolbox of functional block copolymers via free-radical addition of mercaptans

This work demonstrates the applicability of the free-radical addition of ω-functional mercaptans onto 1,2-polybutadienes as a modular synthetic pathway toward a toolbox of diverse functional block copolymers. Functional groups included, for instance electrolytes (carboxylic acid and amine), l-amino acid, and fluorocarbon. The number of functional groups attached to the polymer was lower than that of double bonds reacted (degree of functionalization=50–85%, typically 70–80%) due to cyclization of two neighboring units, but the narrow molecular-weight distribution of the parent (co)polymer was always maintained.     

Industry 4.0 as a Cyber-Physical System study

Advances in computation and communication are taking shape in the form of the Internet of Things, Machine-to-Machine technology, Industry 4.0, and Cyber-Physical Systems (CPS). The impact on engineering such systems is a new technical systems paradigm based on ensembles of collaborating embedded software systems. To successfully facilitate this paradigm, multiple needs can be identified along three axes: (i) online configuring an ensemble of systems, (ii) achieving a concerted function of collaborating systems, and (iii) providing the enabling infrastructure. This work focuses on the collaborative function dimension and presents a set of concrete examples of CPS challenges. The examples are illustrated based on a pick and place machine that solves a distributed version of the Towers of Hanoi puzzle. The system includes a physical environment, a wireless network, concurrent computing resources, and computational functionality such as, service arbitration, various forms of control, and processing of streaming video. The pick and place machine is of medium-size complexity. It is representative of issues occurring in industrial systems that are coming online. The entire study is provided at a computational model level, with the intent to contribute to the model-based research agenda in terms of design methods and implementation technologies necessary to make the next generation systems a reality.     

Carbon nano-onion composites: Physicochemical characteristics and biological activity

Carbon nano-onion/surfactant (CNO/surfactant) composites offer the possibility to easily produce the soluble nanostructures. That approach combines the hydrophilicity of surfactants with the robustness of carbon structures to produce composites with superior and unusual physicochemical properties. We used the following surfactants: hexadecyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol (Triton X-100), and polyethylene glycol sorbitan monolaurate (Tween 20) to non-covalently modify CNO surfaces. The existence of stable CNO composites are clearly evidenced by direct transmission electron microscopy observations, which are also supported by thermogravimetric analyses. Dynamic light scattering and zeta potential confirmed their dispersion and stability. Additionally, the biological activity of well-dispersed CNO/surfactant composites against a strain of Escherichia coli was assayed. In vitro antimicrobial assays for the composites revealed that only the CNO/CTAB composite decreased cell viability. This activity could be assigned to the simple composite dissociation in water solutions, however antimicrobial properties of the composite are slightly better when compared with pure CTAB. This indicate some synergic effect with respect to the properties of the pure surfactant.     

S-Ribosylhomocysteine analogues modified at the ribosyl C-4 position

4-C-Alkyl/aryl-S-ribosylhomocysteine (SRH) analogues were prepared by coupling of homocysteine with 4-substituted ribofuranose derivatives. The diastereoselective incorporation of the methyl substituent into the 4 position of the ribose ring was accomplished by the addition of methylmagnesium bromide to the protected ribitol-4-ulose yielding the 4-C-methylribitol in 85% yield as single 4R diastereomer. The 4-C hexyl, octyl, vinyl, and aryl ribitols were prepared analogously. Chelation controlled addition of a carbanion to ketones from the Si-face was responsible for the observed stereochemical outcome. Oxidation of the primary alcohol of the 4-C ribitols with catalytic amounts of tetrapropylammonium perruthenate in the presence of N-methylmorpholine N-oxide produced 4-C-alkylribono-1,4-lactones in high yields. Mesylation of the latter compounds at the 5-hydroxyl position and treatment with a protected homocysteine thiolate afforded protected 4-C-alkyl/aryl-SRH analogues as the lactones. Reduction with lithium triethylborohydride and successive global deprotections with TFA afforded 4-C-alkyl/aryl SRH analogues. These analogues might impede the S-ribosylhomocysteinase(LuxS)-catalyzed reaction by preventing β-elimination of a homocysteine molecule, and thus depleting the production of quorum sensing signaling molecule AI-2.     

A Comparative Study of Mechanical Properties,Thermal Conductivity,Residual Stresses,and Wear Resistance of Aluminum-Alumina Composites Obtained by Squeeze Casting and Powder Metallurgy

Squeeze casting and powder metallurgy techniques were employed to fabricate AlSi12/Al₂O₃ composites, which are lightweight structural materials with potential applications in the automotive industry. The impact of the processing route on the material properties was studied. Comparative analyses were conducted for the Vickers hardness, flexural strength, fracture toughness, thermal conductivity, thermal residual stresses, and frictional wear. Our results show that the squeeze cast composite exhibits superior properties to those obtained using powder metallurgy.

     

Detailed Insight into the Interaction of Bicyclic Somatostatin Analogue with Cu(II) Ions

Somatostatin analogues are useful pharmaceuticals in peptide receptor radionuclide therapy. In previous studies, we analyzed a new bicyclic somatostatin analogue (BCS) in connection with Cu(II) ions. Two characteristic sites were present in the peptide chain: the receptor- and the metal-binding site. We have already shown that this ligand can form very stable imidazole complexes with the metal ion. In this work, our aim was to characterize the intramolecular interaction that occurs in the peptide molecule. Therefore, we analyzed the coordination abilities of two cyclic ligands, i.e., P1 only with the metal binding site and P2 with both sites, but without the disulfide bond. Furthermore, we used magnetic circular dichroism (MCD) spectroscopy to better understand the coordination process. We applied this method to analyze spectra of P1, P2, and BCS, which we have described previously. Additionally, we analyzed the MCD spectra of P3 ligand, which has only the receptor binding site in its structure. We have unequivocally shown that the presence of the Phe-Trp-Lys-Thr motif and the disulfide bond significantly increases the metal binding efficiency.