The present work is focused on testing enzyme-based agents for the partial dissolution of calcium pyrophosphate (CaPPi) deposits in the cartilages and synovial fluid of patients with pyrophosphate arthropathy (CPPD disease). Previously, we suggested that inorganic pyrophosphatases (PPases) immobilized on nanodiamonds of detonation synthesis (NDs) could be appropriate for this purpose. We synthesized and characterized conjugates of NDs and PPases from Escherichia coli and Mycobacterium tuberculosis. The conjugates showed high enzymatic activity and resistance to inhibition by calcium and fluoride. Here, we tested the effectiveness of pyrophosphate (PPi) hydrolysis by the conjugates in an in vitro model system simulating the ionic composition of the synovial fluid and in the samples of synovial fluid of patients with CPPD via NMR spectroscopy. The conjugates of both PPases efficiently hydrolyzed triclinic crystalline calcium pyrophosphate (t-CPPD) in the model system. We evaluated the number of phosphorus-containing compounds in the synovial fluid, showed the possibility of PPi detection in it, and estimated the hydrolytic activity of the PPase conjugates. The soluble and immobilized PPases were able to hydrolyze a significant amount of PPi (1 mM) in the synovial fluid in short periods of time (24 h). The maximum activity was demonstrated for Mt-PPase immobilized on ND-NH-(CH2)6-NH2 (2.24 U mg-1). Copyright © 2020 American Chemical Society.The infrared spectrum (IR) characteristic peaks of amide I, amide II, and amide III bands are marked as amide or peptide characteristic peaks. Through the nuclear magnetic resonance study, N-methylacetamide has been determined to have six fine components, which include protonation, hydration, and hydroxy structures. Then the independent IR spectrum of every component in N-methylacetamide is calculated by using the density functional theory quantum chemistry method, and the contribution of each component to amide I, II, and III bands is analyzed. The results of this research can help to explain the formation of the amide infrared spectrum, which has positive significance in organic chemistry, analytical chemistry, and chemical biology. Copyright © 2020 American Chemical Society.N-Linked glycosylation of the fragment crystallizable (Fc) domain of immunoglobulin G (IgG) is considered a significant modulator of antibody functions, which is known to be subclass-specific. STA-9090 in vivo As mice are the most widely used model organisms in immunological research, determining the variation in Fc glycosylation among each murine IgG subclass in different physiological or pathological statuses is beneficial for studying how the IgG subclass effector function is affected by Fc glycosylation. In this study, we established a method to quantify murine IgG Fc glycoforms normalized to the protein abundance at a subclass-specific level for various mouse strains using multiple reaction monitoring. The glycoform level was normalized to the subclass protein abundance (subclass-specific peptide intensity) in each IgG subclass to eliminate the contribution from the subclass protein abundance. Both good linearity and high repeatability of the method were validated by investigating a mixed mouse serum sample. The method was applied to quantify the differences in subclass-specific IgG Fc N-glycoforms between systemic sclerosis (SSc) mice and healthy control mice. The results demonstrated that each IgG subclass had its own characteristic-altered glycosylation, implying the close association of subclass-specific IgG Fc glycosylation with SSc in mice. This report demonstrates a method with great reliability and practicality that has promising potential for the relative quantitation of subclass-specific IgG Fc N-glycoforms in multiple mouse models. Copyright © 2020 American Chemical Society.Multicomponent self-assembly of peptides is a powerful strategy to fabricate novel functional materials with synergetic properties that can be used for several nanobiotechnological applications. In the present study, we used a coassembly strategy to generate an injectable ultrashort bioactive peptide hydrogel formed by mixing a dipeptide hydrogelator with a macrophage attracting short chemotactic peptide ligand. Coassembly does not impede hydrogelation as shown by cryo-transmission electron microscopy (cryo-TEM), scanning electron microscopy, and rheology. Biocompatibility was shown by cytotoxicity assays and confocal microscopy. The hydrogels release the entrapped skin antibiotic ciprofloxacin, among others, in a slow and continuous manner. Such bioinspired advanced functional materials can find applications as wound dressing materials to treat chronic wound conditions like diabetic foot ulcer. Copyright © 2020 American Chemical Society.Natural rubber (NR) nanocomposites were prepared by filling cornmeal graphene (CGE) to improve its mechanical properties and thermal properties, and CGE was modified with coupling agents to improve its dispersion in NR. The mechanical properties, wear resistance, thermal stability, and morphology of CGE/NR nanocomposites were studied. The results showed that when NR was 100 phr (parts per hundred rubbers), the CGE was 0.02 phr, and the coupling agent KH590 was 2 phr, the thermal stability and mechanical properties of the CGE/NR nanocomposites were the best. Compared with NR, the thermal conductivity of the nanocomposites increased by 6.0 mW/g, and the decomposition temperature increased by 37 °C. The mechanical properties and wear resistance of KH590-CGE/NR nanocomposites were the best, and compared with NR, the tensile strength, elongation at break, and wear resistance of KH590-CGE/NR nanocomposites increased by 16, 14, and 17%, respectively. The compatibility and dispersion of KH590-CGE/NR nanocomposites were the best. Copyright © 2020 American Chemical Society.Due to lactose intolerance, there is a growing need for lactose-free or low-lactose dairy products. Herein, a combination of three membrane technologies (UF, electrodialysis (ED), and nanofiltration (NF)) was used as a novel green technology to replace the enzymatic preparation of low-lactose milk powder in the traditional industry. In which, large molecules such as proteins and fats are first retained using UF, mineral salt was intercepted and re-added into milk by electrodialysis, and finally, lactose is recovered by NF. Finally, low-lactose milk powder with a lactose content of less than 0.2% was obtained; meanwhile, the high purity (95.7%) of lactose powder could be effectively reclaimed from the NF concentrate (lactose concentrate). The whole membrane process is based on the physical pore size screening mechanism, without adding any chemical reagents with minimal impact on the physical and chemical properties of milk. These results indicate that process development and optimization coupling of three membrane technologies is very promising in preparing low-lactose milk powder and recovering lactose.STA-9090 in vivo
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