Protein Bovine Serum Research Articles

Investigating changes of proteome in the bovine milk serum after retort processing using proteomics techniques.

The objective of this study was to investigate the changes of the proteins in bovine milk serum after retort processing by label‐free quantification proteomics techniques. A total of 96 and 106 proteins were quantified in control group (CG) and retort group (RG), respectively. Hierarchical clustering analysis of the identified milk serum proteins showed a decrease in the abundance of most proteins, such as serum albumin, lactoperoxidase, lactotransferrin, and complement C3, and an increase in the abundance of other proteins such as κ‐casein, lipocalin 2, and Perilipin. Student's t‐test showed 21 proteins significantly differential abundance between CG and RG (p < .05), of which intensity‐based absolute quantification (iBAQ) of five proteins decreased and iBAQ of 16 proteins increased. Bioinformatics analysis demonstrated that retort processing increased the digestibility of proteins, but this improvement was offset by a decrease in the digestibility of proteins caused by protein modification. Our results provide insight into the proteome of retort sterilized milk for the first time. Given the extremely high security of retort sterilized milk, the proteome of bovine milk serum changes after retort sterilization exposed in this study will contribute to the formula design of retort sterilized milk products.

Photoelectrocatalytic mechanism of PEDOT modified filtration membrane

The generation of free radicals is the key to the photocatalytic efficiency. In this study, the degradation mechanism of photoelectrocatalysis (PEC) membrane could be adequately explained by exploring the generation pathway of different free radicals. The PEC membrane was prepared by gas phase polymerization of poly (3, 4-ethylene dioxythiophene) (PEDOT) on non-woven fabric, industrial filter cloth, ceramic membrane and polyvinylidene fluoride (PVDF) membrane, respectively. Three-dimensional fluorescence test showed that the optimal degradation of mixed or monomer contamination (bovine serum protein, sodium humate, and sodium alginate) was achieved by modified ceramic membrane under PEC condition. As for self-cleaning experiment, the membrane resistance decreased 65.7% when the reaction conditions changed from dark to PEC for 30 min. Combined with the characterization results, PEDOT as photocapacitance extended electron lifetime and promoted free radical generation. This system was mainly dependent on superoxide free radicals (0.01 mmol/L) and singlet oxygen (0.10 mmol/L), which came from energy and electron transfer. Oxygen vacancy could adsorb oxygen to produce superoxide radicals, which was further oxidized to singlet oxygen. In addition, the π-electron conjugated system of PEDOT accelerated the hole transfer and the separation of electrons and holes. Also, this study provided a new view of reactive oxygen species generation mechanism from PEDOT modified membrane.

A Photo-Responsive Porphyrin-Mn@Choles Complex for Bacteria Treatment

Biocompatible photo-driven producers of singlet oxygen can inhibit the growth of drug-resistant bacteria and tumors. In order to develop bacteria targeting generator of singlet oxygen for tumor and bacterial treatment, a metal porphyrin liposome (Phy–Mn–Ls) was prepared by the metal coordination reaction and self-assembly of porphyrin compounds with bacteria targeting polymer (HS–PEG–chol). The photo-driven production of 1O2, binding with bovine serum protein (BSA) and lipase, toxicity to MCF-7 breast cancer cells and inhibitory effect on the growth of Escherichia coli have been investigated. Fluorescence analysis results show that Phy–Mn–Ls can bind to lipase, and it shows less effect on the conformation of BSA and is low cytotoxicity without irradiation. In particular, the good biocompatibility made Phy–Mn–Ls exhibit good photosensitive antibacterial activity and anti-tumor properties. The results demonstrate that the coordination of HS–PEG–chol with metal-phorphrin coodination is an effective way to develop bacteria targeting nano-complexes (Phy–Mn–Ls) for lipase affinity and photodriven bacteria treatment.

Probing the roles of pH and ionic strength on electrostatic binding of tetracycline by dissolved organic matters: Reevaluation of modified fitting model

The binding performance of dissolved organic matters (DOM) plays a critical role in the migration, diffusion and removal of various residual pollutants in the natural water environment. In the current study, four typical DOMs (including bovine serum proteins BSA (proteins), sodium alginate SAA (polysaccharides), humic acid HA and fulvic acid FA (humus)) are selected to investigate the binding roles in zwitterionic tetracycline (TET) antibiotic under various ionic strength (IS = 0.001–0.1 M) and pH (5.0–9.0). The dialysis equilibration technique was employed to determine the binding concentrations of TET, and the influence of IS and pH on binding performance was evaluated via UV–vis spectroscopy, total organic carbon (TOC), and Excitation-Emission-Matrix spectra (EEM), zeta potentials and molecule size distribution analysis. Our results suggested that carboxyl and phenolic hydroxyl were identified as the main contributors to TET binding based on the fourier transform infrared spectroscopy (FTIR) analysis, and the binding capability of four DOMs followed as HA > FA » BSA > SAA. The biggest binding concentrations of TET by 10 mg C/L HA, FA, BSA and SAA were 0.863 μM, 0.487 μM, 0.084 μM and 0.086 μM, respectively. The higher binding capability of HA and FA is mainly attributed to their richer functional groups, lower zeta potential (HA/FA = −15.92/-13.54 mV) and the bigger molecular size (HA/FA = 24668/27750 nm). IS significantly inhibits the binding interaction by compressing the molecular structure and the surface electric double layer, while pH had a weak effect. By combining the Donnan model and the multiple linear regression analysis, a modified Karickhoff model was established to effectively predict the binding performance of DOM under different IS (0.001–0.1 M) and pH (5.0–9.0) conditions, and the R2 of linear fitting between experiment-measured logKDOC and model-calculated logKOC were 0.94 for HA and 0.91 for FA. This finding provides a theoretical basis for characterizing and predicting the binding performance of various DOMs to residual micropollutants in the natural water environment.

Anti-inflammatory and Anti-arthritic Potentials of Maesa Montana Roots

Maesa Montana is a flowering plant of the Myrsinaceae family, which is locally known as ramjani. The current study aimed to evaluate the in-vitro anti-arthritic and anti-inflammatory activities of the root extract of this plant. The anti-inflammatory performances were measured by the hindrance of egg white denaturation, and anti-arthritic activity was investigated by Bovine serum protein. In the anti-inflammatory activity test, the methanolic root extract of this plant showed 69.29 ± 1.19 % of inhibition at a concentration of 1000 µg/mL and standard drug exhibited 90.11 ± 1.45 % of inhibition at the same concentration. Furthermore, in the anti-arthritic activity test, the extract demonstrated 68.18 ± 1.34 % of inhibition at a concentration of 1000 µg/mL whereas the standard diclofenac drug showed 90.65 ± 1.19 % of inhibition at the same concentration. These results revealed that the root extract of this plant possesses significant anti-arthritic and anti-inflammatory activities based on the inhibition of BSA and protein denaturation. HIGHLIGHTS Methanol soluble compounds extraction from the roots of Maesa Montana Anti-inflammatory activity determination using egg albumin Anti-arthritic activity measurement using bovine serum albumin GRAPHICAL ABSTRACT

Interactions of blueberry anthocyanins with whey protein isolate and bovine serum protein: Color stability, antioxidant activity, in vitro simulation, and protein functionality

The interaction of proteins with anthocyanins (ACNs) gives rise to significant improvements in their functional properties. To explore the interactions between whey protein isolate (WPI)/bovine serum albumin (BSA) and blueberry ACNs, light (5000 Lux, 7 days), heat (85 °C, 2 h), sucrose (0.25 mg/mL), and vitamin C (0.15 mg/mL) were used to accelerate the degradation of ACNs. Through the observation of color changes and variations in the free radical scavenging rates, WPI and BSA were found to protect the ACNs to varying degrees. Moreover, WPI/BSA exhibited increased solubilities, foaming and emulsifying properties, and changed thermal stabilities and protein structures, in addition to decreased surface hydrophobicities and zeta potentials. Furthermore, the addition of WPI/BSA increased the number of ACN monomers in a simulated digestion system, as determined by high-performance liquid chromatography-mass spectrometry. Therefore, by studying the interactions between proteins and ACNs, we can provide a strategy and theoretical basis for determining the steady-state of ACNs in blueberry products.

Pharmacological support to anti-arthritic prospective of physostigmine: a new approach.

Rheumatoid arthritis (RA) is a slowly progressing inflammatory autoimmune disease. Several features are involved in the RA pathogenesis in addition to environmental and genetic factors. Previously it has been reported that acetyl cholinesterase (AChE) activity is enhanced in old age and may contribute in the progression of RA. The current experimental work was projected to assess the activity of physostigmine (a cholinesterase inhibitor) for treatment of RA. In vitro and in vivo approaches were used for such evaluation. However, enzyme linked immunosorbent assays (ELISA) was performed to determine the concentrations of Prostaglandins E2 (PGE2) and tumor necrosis factor-α in arthritic rats after treatment with physostigmine. Moreover, anti-oxidant assays were employed to calculate the level of super oxide dismutase (SOD) and catalase peroxidase (CAT) in tissue of treated animals. The results claimed the dose dependent protective and stabilizing effect of physostigmine on denaturation of albumin (egg and bovine serum) protein and human red blood cell membrane, respectively, through in vitro studies. Furthermore, the physostigmine (10 and 20mg/kg) significantly (p < 0.001) reduced the swelling of paw after induction of arthritis with formaldehyde or complete Freund's adjuvant (CFA) as compared to arthritic control animals. Moreover, significant (p < 0.001) reduction in the levels of inflammatory markers (PGE2 and TNF-α) at doses of 10 and 20mg/kg of physostigmine has been observed in ELISA test. Likewise, there was a prominent rise in levels of SOD and CAT in animals treated with physostigmine. These findings pharmacologically conclude the anti-arthritic effect of physostigmine.

Interaction of dirhenium(III) tryptophan complex compound with DNA and protein

We report about the interactions of dirhenium(III) compound cis-[Re2(Trp)2Cl4(CH3CN)2]Cl2 (I) with bovine serum protein (BSA) and guanine (G4) quadruplexes DNA by UV-Vis titration. Addition of I to BSA led to the interaction between these compounds with binding constant 5.6103 M–1 and hyperchromism (20.9%) of the main protein absorption band (280 nm). These results support our assumption about formation of the additional conjugated systems during the process of interaction with BSA. Stabilization of the quadruple bonded rhenium(III) complex compound was shown in the presence of BSA (the rate of destruction was reduced), that may be explained by interaction between amino acid residues of BSA and quadruple bond of dirhenium(III) complex compound. In addition, we have obtained data about strong hyperchromism (up to 100%) and significant shift of the maximum of absorption (blue shift) towards UV (2–9 nm) and visible (22 nm) regions in the spectra of mixtures G4s and I, that, in our opinion, correlated with a conformational change in DNA and with formation of additional conjugated systems around quadruple bond of I. In a whole, our work confirms the strong binding activity of a cluster dirhenium(III) compound towards G4 quadruplexes, that exceed the binding activity to proteins and witness to preferential interactions of I with G4 DNA in a living cell. These results may be used in DNA "silencing technology" and "antisense therapy".

Effect of Cr@RGO structure on microstructure and properties of RGO/CuCr25 composite

CuCr alloy with high Cr content (20–50 wt.%) is the main contact material for medium voltage and high current vacuum interrupters. However, the influence of network distribution of Cr particles affect the conductivity of CuCr alloy, and its properties strongly depend on the size of Cr particles. In this paper, Cr@RGO (Cr powder coated with reduced GO) was prepared by BSA (bovine serum protein) electrostatic assembly method, and then RGO/CuCr composites with different graphene content were prepared by vacuum hot pressing sintering process. The results show that the size of Cr particles decreases with the increase of graphene content and the network of Cr particles became fractured. When the content of RGO is 3.0 wt.%, the size of Cr phase is 19.9 μm, which is 23.8% less than that of CuCr25 of 26.1 μm. The Brinell hardness and electrical conductivity of 3.0 wt.% RGO/CuCr composite are 102.5 HB and 52.9% IACS, which is increased by 8% and 6% in contrast with that of CuCr25. And the Preparation of RGO/CuCr is simple, feasible, replicable and easy to achieve the goal of the industrial preparation.

Preparation of antifouling poly (ether ether ketone) hollow fiber membrane by ultraviolet grafting of polyethylene glycol

Polyethylene glycols (PEG) with relative molecular weights of 2,000, 10,000, 20,000, and 50,000 were grafted onto the surface of Poly (ether ether ketone) (PEEK)hollow fiber membranes respectively by UV irradiation grafting methods. The surface morphology, pore structure, and filtration performance of the PEEK and PEEK-g-PEG membranes were investigated in detail. Moreover, the bovine serum protein(BSA)was used as a model foulant to characterize the antifouling performance of the membrane. The effects of grafting density and grafting chain length on membrane permeability and antifouling performance were explored. The results of surface morphology showed that after grafting polyethylene glycol, there was no significant decrease of the surface porosity. When the relative molecular weight of PEG is 2000, the normalized water flux of the PEEK-g-PEG2000 membrane is increased to 3.38, but the flux recovery rate is only 79.9 %; when the molecular weight of PEG is 50,000, the flux recovery rate of the PEEK-g-PEG50000 membrane is 99.2 %, but the normalized water flux decreased to 0.73. Therefore, the increase of hydrophilicity can improve the permeability of the membrane, but the long grafting chains easily plugs the membrane pores and reduces the permeability of the membrane. The research found that the grafting density and grafting chain length have different mechanisms of action to prevent the adsorption of foulants to the polymer matrix. The antifouling performance of PEEK membrane can be effectively improved by regulating the grafting density and grafting chain length.

The interaction of graphene oxide-silver nanoparticles with trypsin: Insights from adsorption behaviors, conformational structure and enzymatic activity investigations

In this work, we synthesized graphene oxide-silver nanoparticles (GO-AgNPs) hybrids by one-pot method. Since there are relatively few reports on whether GO-AgNPs bind and change the structure and function of trypsin, A variety of methods were employed to systematically characterize the molecular interaction between GO-AgNPs and trypsin. Results exhibited that GO-AgNPs bound with trypsin to form a ground state complex. GO-AgNPs had higher adsorption capacity for trypsin compared with single GO. Langmuir-Blodgett assembly method was used to confirm that AgNPs did not interfere with the adsorption of trypsin by GO. The secondary structure and the microenvironment of amino acid residues of trypsin were altered after interacting with GO-AgNPs. In addition, GO-AgNPs can enhance the activity of trypsin and promote the hydrolysis of bovine serum protein (BSA) by trypsin. These findings provide important support for the application of GO-based nanocomposites in the efficient immobilization of enzymes.

A Simple Method for In-Depth Proteome Analysis of Mammalian Cell Culture Conditioned Media Containing Fetal Bovine Serum.

A conditioned medium of a cell culture is widely used for various biological applications and frequently analyzed to characterize the functional proteins responsible for observed biological functions. However, a large number of abundant proteins in fetal bovine serum (FBS), usually included in the conditioned medium of a mammalian cell culture medium, hampers in-depth proteomic analysis by liquid chromatography–tandem mass spectrometry (LC-MS/MS). For a deep proteomic analysis of a conditioned medium by LC-MS/MS, we developed a simple albumin depletion approach coupled with data-independent acquisition (DIA)-mode LC-MS/MS for the conditioned medium of mammalian cells in this study. The results showed that this approach enabled the detection of more than 3700 cell-derived proteins in the cell culture supernatant containing FBS. We further demonstrated the potency of this approach by analyzing proteins in the conditioned media of HeLa cells with and without tumor necrosis factor (TNF) stimulation: >40 differentially accumulated proteins, including four cytokines, upon TNF stimulation were identified in the culture media, which were hardly detected by conventional proteome approaches in the literature.

Fabrication of Zinc Protoporphyrin-Modified Gold Electrode for Sensitive and Fast Detection of Vascular Endothelial Growth Factor

Vascular endothelial growth factor (VEGF) is directly related to cancer growth and its distant spread, and thus, it is considered a promising biomarker for diagnosis and post-treatment monitoring of patients with malignancies. Zinc protoporphyrin (ZnPP) is a zinc-centered raw purple compound (protoporphyrin) that has unique optical and electrochemical characteristics. In this study, we used a ZnPP-modified gold electrode to generate a chemical bond with Avastin by self-assembly and fabricate a Au/ZnPP/Avastin electrode. Bovine serum protein (BSA) was added to the electrode to prevent non-specific linkage with biomolecules. The prepared Au/ZnPP/Avastin/BSA electrodes were used for the detection of VEGF by cyclic voltammetry and amperometry. The optical properties of ZnPP were analyzed with an ultraviolet/visible/near-infrared spectrometer and a photoluminescence spectrometer. The structural and hydrophilic/hydrophobic properties of the ZnPP-modified gold electrodes were investigated by Fourier-transform infrared spectroscopy and contact angle gauge, respectively. VEGF was detected with the Au/ZnPP/Avastin/BSA electrodes prepared either with (w/LT) or without light treatment (w/o LT). The w/LT electrode showed a linear range and a sensitivity of 0.1 pg/mL–10 ng/mL and 6.52 μA/log(pg/mL)-cm2, respectively; the corresponding values for the w/o LT electrode were 10 pg/mL–10 ng/mL and 3.15 μA/log(pg/mL)-cm2, respectively. The w/LT electrode had good specificity for VEGF and was minimally influenced by other molecules. The excellent detection range, high sensitivity, and high selectivity for VEGF detection indicate that Au/ZnPP/Avastin electrodes have great potential for diagnostic and prognostic applications in patients with malignancies.

Anti-inflammatory and antitumor activities of the chloroform extract and anti-inflammatory effect of the three diterpenes isolated from Salvia ballotiflora Benth

BackgroundDrugs used for the treatment of diseases associated with chronic inflammation, such as cancer and rheumatoid arthritis have the potential to cause undesirable side-effects, which might result in patients ending treatment prematurely. However, plants are a viable option for the treatment of inflammatory diseases. In this study, we assessed the in vivo and in vitro anti-inflammatory activity, and the antitumor effects of the chloroform extract of Salvia ballotiflora (ECL). The pro-apoptotic effects of ECL in CT26 cells were also determined.MethodsThe chloroform extract of Salvia ballotiflora (ECL) was standardized using 19-deoxyicetexone (DEOX) as a phytochemical marker. The anti-inflammatory activity of ECL was determined on acute and chronic inflammatory models using the TPA-induced mouse ear edema assay. The antitumor activity of ECL was evaluated by the subcutaneous inoculation of CT26 cells on the back of Balb/c mice. In vitro CT26 cell death induced by ECL was determined by Annexin V/propidium iodide staining assay using flow cytometry. ECL and the diterpenes isolated from the chloroform extract included 19-deoxyicetexone (DEOX), icetexone (ICT), and 7,20-dihydroanastomosine (DAM), which were tested in LPS-stimulated J774A.1 macrophages to quantify pro-inflammatory cytokine levels. The in vitro anti-arthritic activity of ECL was determined using the bovine serum protein (BSP) denaturation assay.ResultsECL exerted anti-inflammatory activities in acute (84% of inhibition, 2 mg/ear) and chronic models (62.71%, at 100 mg/kg). ECL showed antitumor activity at 200 mg/kg and 300 mg/kg, reducing tumor volume by 30 and 40%, respectively. ECL (9.5 μg/mL) induced in vitro apoptosis in CT26 cells by 29.1% (48 h of treatment) and 93.9% (72 h of treatment). ECL (10 μg/ml) decreased levels of NO (53.7%), pro-inflammatory cytokines IL-6 (44.9%), IL-1β (71.9%), and TNF-α (40.1%), but increased the production of the anti-inflammatory cytokine IL-10 (44%). The diterpenes DEOX, ICT, and DAM decreased levels of NO (38.34, 47.63, 67.15%), IL-6 (57.84, 60.45, 44.26%), and TNF-α (38.90, 31.30, 32.83%), respectively. ECL showed in vitro antiarthritic activity (IC50 = 482.65 μg/mL).ConclusionsECL exhibited anti-inflammatory and anti-tumor activities. Furthermore, the diterpenes DEOX, DAM, and ICT showed anti-inflammatory activity by reducing levels of NO, TNF-α, and IL-6.

Study on the fluorescence properties of the interaction between felodipine and bovine serum protein

The interaction between felodipine and bovine serum protein was studied, the optimal experimental conditions were selected, and the fluorescence quenching mechanism was discussed. The interaction between filodipine and bovine serum protein was determined by UV spectrophotometry, and the optimal experimental conditions were selected by control variable method. The mechanism of fluorescence quenching in the system was explored by fluorescence spectrophotometry. The fluorescence intensity of the system between felodipine and bovine serum protein was the most obvious under the experimental conditions of buffer solution pH 7.4, felodipine concentration 8.0*10-4mol/L, reaction time 30min and 25°C. Static fluorescence quenching caused by the formation of complex compounds.

Toward an automated workflow for the study of plasma protein-drug interactions based on capillary electrophoresis-frontal analysis combined with in-capillary mixing of interacting partners

Capillary electrophoresis-frontal analysis (CE-FA) together with mobility shift affinity CE is the most frequently used mode of affinity CE for a study of plasma protein-drug interactions, which is a substantial part of the early stage of drug discovery. Whereas in the classic CE-FA setup the sample is prepared by off-line mixing of the interaction partners in the sample vial outside the CE instrument and after a short incubation period loaded into the capillary and analysed, in this work a new methodological approach has been developed that combines CE-FA with the mixing of interacting partners directly inside the capillary. This combination gives rise to a fully automated and versatile methodology for the characterization of these binding interactions besides a substantial reduction in the amounts of sample compounds used. The minimization of possible experimental errors due to the full involving of sophisticated CE instrument in the injection procedure, mixing and separation instead of manual manipulation is another fundamental benefit.The in-capillary mixing is based on the transverse diffusion of laminar flow profile methodology introduced by Krylov et al. using its multi-zone injection modification presented by Řemínek at al.. Actually, after the method optimization, the alternate introduction of six plugs of drug and six plugs of bovine serum protein in BGE, each injected for 3 s at a pressure of -10 mbar (-1 kPa) into the capillary filled by BGE, was found to be the best injection procedure. The method repeatability calculated as RSDs of plateau highs of bovine serum albumin and propranolol as model sample compounds were better than 3.44 %. Its applicability was finally demonstrated on the determination of apparent binding parameters of bovine serum albumin for basic drugs propranolol and lidocaine and acid drug phenylbutazone. The values obtained by a new on-line CE-FA methodology are in agreement with values estimated by classic off-line CE-FA, as well as with literature data obtained using different techniques.

Peptidome comparison following gastrointestinal digesta of bovine versus caprine milk serum

Infant formula is used as a supplement for newborns. Although bovine milk-based infant formulas dominate the market, caprine milk-based infant formula has attracted increasing attention because of its lower allergenicity. This study compared the digestive peptidome of bovine and caprine milk serum proteins by using in vitro infant simulating conditions. The result showed that the degradation pattern of milk proteins was similar, whereas the digestive rates of milk proteins differed between bovine and caprine milks. Several proteins, such as α-lactalbumin (LALBA), β-lactoglobulin (LGB), serum amyloid A protein (SAA1), glycosylation-dependent cell adhesion molecule 1 (GLYCAM1), and lactotransferrin (LTF), released more peptides during digestion of caprine milk serum than during digestion of bovine milk serum; however, more peptides derived from αS1-casein (CSN1S1) were found in bovine digesta. In addition, antimicrobial-related peptides were mostly only found in caprine intestinal digesta. The results of this study may be useful in understanding the digestion characteristics of milk serum proteins and providing guidance on the improvement of infant formula.

Changes in the milk serum proteome after thermal and non-thermal treatment

Milk serum contains many immune-active proteins that are sensitive to heat treatment. This study compared the effects of thermal (63 °C, 30 min; 72 °C, 15 s; 85 °C, 5 min) and non-thermal (ultraviolet-C, UV-C; thermo-ultrasonication, TUS) treatments on bovine milk serum proteins by using label-free LC-MS/MS-based proteomics. UV-C (4500 J/L) and TUS (60 W, 6 min) treatments achieved a 5log microbial reduction as determined by plate counting. Proteomics showed that e.g., complement proteins, xanthine dehydrogenase/oxidase, and fatty acid-binding protein decreased significantly (p˂0.05, |fold change|˃1) after thermal treatments, and almost no lactoferrin, immunoglobulin, and lactoperoxidase was retained after heating at 85 °C for 5 min, whereas these proteins were mostly retained after non-thermal treatments. Most of these heat-sensitive proteins were located in membrane and extracellular regions and were involved in cellular and metabolic processes, response to stimulus, binding, immune process and catalytic functions. Finally, part of the proteomics results were verified by ELISA. This study thus provided insights for the development of optimized thermal and novel non-thermal treatments for dairy processing. Industrial relevanceAs alternatives to thermal processing technique, UV-C and ultrasonication showed a great potential in the processing of milk. This study not only showed that UV-C and ultrasonication were able to largely reduce the microbial load of raw milk, but also better retained the immune-related milk serum proteins than thermal processing, especially for the UV-C treatment. ELISA assays also demonstrated that the LC-MS/MS based proteomics technology used in this study was a robust method for quantifying damage to the milk serum proteome upon processing. Taken together, this study provided insights for development of optimized thermal and novel non-thermal techniques for dairy processing.

Effects of Surface Chemistry and Topology on the Kinesin-Driven Motility of Microtubule Shuttles.

Nanoscale transport using the kinesin-microtubule system has been successfully used in applications ranging from self-assembly, to biosensing, to biocomputation. Realization of such applications necessitates robust microtubule motility particularly in the presence of complex sample matrices that can affect the interactions of the motors with the surface and the transport function. In the present work, we explored how the chemical nature and nanoscale topology of various surfaces affected kinesin-microtubule transport. Specifically, we characterized microtubule motility on three distinct interfaces: (i) surfaces modified with self-assembled monolayers (SAMs) displaying three different terminal groups, (ii) SAM-modified surfaces with adsorbed fetal bovine serum (FBS) proteins, and (iii) surfaces where the FBS layer was silicified to preserve an underlying surface topology. The composition and topology of each surface was confirmed with a number of techniques including X-ray photoelectron spectroscopy (XPS), water contact angle, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The majority of surfaces, with the exception of those with the hydrophobic SAM, supported gliding motility consistent with the glass control. Differences in the displacement, velocity, and trajectory of the leading tip of the microtubule were observed in relation to the specific surface chemistry and, to a lesser extent, the nanoscale topology of the different substrates. Overall, this work broadens our understanding of how surface functionality and topology affect kinesin-based transport and provides valuable insights regarding future development of biosensing and probing applications that rely on biomolecular transport.

Characterizing the changes of bovine milk serum proteins after simulated industrial processing

This study investigated the changes and lactose glycosylation of milk serum proteins under simulated industrial processing conditions, including raw milk (R), holder pasteurization (L), high temperature short time pasteurization (H), extended shelf life (E), ultra-high temperature sterilization (U) and spray-drying (S). Through label-free proteomics, 433 proteins were identified in the samples. Several immune-related proteins, such as lactoferrin, complement C3, lactadherin, cystain, and lactoperoxidase, decreased in abundance after severe thermal treatments, while the abundance of caseins increased. No immunoglobulins and xanthine oxidase could be detected in milk after E, U or S treatments while 30%–60% of immunoglobulins was retained after pasteurizations. In detail, lactoferrin showed a better retention in H treatment while IgG showed a better retention in L treatment. UPLC-MS results showed that a slight lactose glycosylation occurred to α-LA and β-LG after severe thermal treatments (E, U and S). In addition, the results of LC-MS/MS based proteomics were verified by determining the lactoferrin and IgG content using ELISA. The observations here would update current information on the changes of milk proteins during traditional thermal processing and help to optimize current dairy processing.