Gel-Filtration Chromatography

Mapping a sustainable approach: biosynthesis of lactobacilli-silver nanocomposites using whey-based medium for antimicrobial and bioactivity applications

This study explores a sustainable approach for synthesizing silver nanocomposites (AgNCs) with enhanced antimicrobial and bioactivity using safe Lactobacillus strains and a whey-based medium (WBM). WBM effectively supported the growth of Lactobacillus delbrueckii and Lactobacillus acidophilus, triggering a stress response that led to AgNCs formation. The synthesized AgNCs were characterized using advanced spectroscopic and imaging techniques such as UV‒visible, Fourier transform infrared (FT-IR) spectroscopy, transmission electron (TEM), and scanning electron microscopy with energy dispersive X-ray analysis (SEM-Edx). Lb acidophilus-synthesized AgNCs in WBM (had DLS size average 817.2-974.3 ± PDI = 0.441 nm with an average of metal core size 13.32 ± 3.55 nm) exhibited significant antimicrobial activity against a broad spectrum of pathogens, including bacteria such as Escherichia coli (16.47 ± 2.19 nm), Bacillus cereus (15.31 ± 0.43 nm), Clostridium perfringens (25.95 ± 0.03 mm), Enterococcus faecalis (32.34 ± 0.07 mm), Listeria monocytogenes (23.33 ± 0.05 mm), methicillin-resistant Staphylococcus aureus (MRSA) (13.20 ± 1.76 mm), and filamentous fungi such as Aspergillus brasiliensis (33.46 ± 0.01 mm). In addition, Lb acidophilus-synthesized AgNCs in WBM exhibit remarkable free radical scavenging abilities, suggesting their potential as bioavailable antioxidants. These findings highlight the dual functionality of these biogenic AgNCs, making them promising candidates for applications in both medicine and nutrition.

Serum Extracellular Vesicle Protein Profiling for Prediction of Corneal Transplant Rejection

BACKGROUND

Corneal transplantation is the most common transplant procedure worldwide. Despite immune and angiogenic privilege of the cornea, 50% to 70% of corneal transplants fail in high-risk recipients, primarily because of immune rejection. Therefore, it is crucial to identify predictive biomarkers of rejection to improve transplant survival.

METHODS

In search for predictive biomarkers, we performed proteomics analysis of serum extracellular vesicles (EVs) in a fully major histocompatibility complex-mismatched (C57BL/6-to-BALB/c) murine corneal transplantation model, wherein 50% of transplants undergo rejection by day 28 following transplantation.

RESULTS

Our time course study revealed a decrease in the number of serum EVs on day 1, followed by a gradual increase by day 7. A comparative analysis of proteomics profiles of EVs from transplant recipients with rejection (rejectors) and without rejection (nonrejectors) found a distinct enrichment of histocompatibility 2, Q region locus 2, which is a part of major histocompatibility complex-class I of donor C57BL/6 mice, in day 7 EVs of rejectors, compared with nonrejectors, syngeneic controls, or naïve mice. In contrast, serum amyloid A2, a protein induced in response to injury, was increased in day 7 EVs of nonrejectors.

CONCLUSIONS

Our findings offer noninvasive EV-based potential biomarkers for predicting corneal allograft rejection or tolerance.

Seaweed-derived phenolic compounds as diverse bioactive molecules: A review on identification, application, extraction and purification strategies

Seaweed, a diverse group of marine macroalgae, has emerged as a rich source of bioactive compounds with numerous health-promoting properties. Among these, phenolic compounds have garnered significant attention for their diverse therapeutic applications. This review examines the methodologies employed in the extraction and purification of phenolic compounds from seaweed, emphasizing their importance in unlocking the full potential of these oceanic treasures. The article provides a comprehensive overview of the structural diversity and biological activities of seaweed-derived phenolics, elucidating their antioxidant, anti-inflammatory, and anticancer properties. Furthermore, it explores the impact of extraction techniques, including conventional methods and modern green technologies, on the yield and quality of phenolic extracts. The purification strategies for isolating specific phenolic compounds are also discussed, shedding light on the challenges and advancements in this field. Additionally, the review highlights the potential applications of seaweed-derived phenolics in various industries, such as pharmaceuticals, cosmetics, and functional foods, underscoring the economic value of these compounds. Finally, future perspectives and research directions are proposed to encourage continued exploration of seaweed phenolics, fostering a deeper understanding of their therapeutic potential and promoting sustainable practices in the extraction and purification processes. This comprehensive review serves as a valuable resource for researchers, industry professionals, and policymakers interested in harnessing the untapped potential of phenolic compounds from seaweed for the betterment of human health and environmental sustainability.

The expansion of liquid biopsies to vascular care: an overview of existing principles, techniques and potential applications to vascular malformation diagnostics

Vascular malformations are congenital lesions that occur due to mutations in major cellular signalling pathways which govern angiogenesis, cell proliferation, motility, and cell death. These pathways have been widely studied in oncology and are substrates for various small molecule inhibitors. Given their common molecular biology, there is now a potential to repurpose these cancer drugs for vascular malformation care; however, a molecular diagnosis is required in order to tailour specific drugs to the individual patient's mutational profile. Liquid biopsies (LBs), emerging as a transformative tool in the field of oncology, hold significant promise in this feat. This paper explores the principles and technologies underlying LBs and evaluates their potential to revolutionize the management of vascular malformations. The review begins by delineating the fundamental principles of LBs, focusing on the detection and analysis of circulating biomarkers such as cell-free DNA, circulating tumor cells, and extracellular vesicles. Subsequently, an in-depth analysis of the technological advancements driving LB platforms is presented. Lastly, the paper highlights the current state of research in applying LBs to various vascular malformations, and uses the aforementioned principles and techniques to conceptualize a liquid biopsy framework that is unique to vascular malformation research and clinical care.

Decoding Cosmetic Complexities: A Comprehensive Guide to Matrix Composition and Pretreatment Technology

Despite advancements in analytical technologies, the complex nature of cosmetic matrices, coupled with the presence of diverse and trace unauthorized additives, hinders the application of these technologies in cosmetics analysis. This not only impedes effective regulation of cosmetics but also leads to the continual infiltration of illegal products into the market, posing serious health risks to consumers. The establishment of cosmetic regulations is often based on extensive scientific experiments, resulting in a certain degree of latency. Therefore, timely advancement in laboratory research is crucial to ensure the timely update and adaptability of regulations. A comprehensive understanding of the composition of cosmetic matrices and their pretreatment technologies is vital for enhancing the efficiency and accuracy of cosmetic detection. Drawing upon the China National Medical Products Administration's 2021 Cosmetic Classification Rules and Classification Catalogue, we streamline the wide array of cosmetics into four principal categories based on the following compositions: emulsified, liquid, powdered, and wax-based cosmetics. In this review, the characteristics, compositional elements, and physicochemical properties inherent to each category, as well as an extensive overview of the evolution of pretreatment methods for different categories, will be explored. Our objective is to provide a clear and comprehensive guide, equipping researchers with profound insights into the core compositions and pretreatment methods of cosmetics, which will in turn advance cosmetic analysis and improve detection and regulatory approaches in the industry.

Purification and Quality Control of Recombinant Proteins Expressed in Mammalian Cells: A Practical Review

In the recent years, there has been a rapid development of new technologies and strategies when it comes to protein purification and quality control (QC), but the basic technologies for these processes go back a long way, with many improvements over the past few decades. The purpose of this chapter is to review these approaches, as well as some other topics such as the advantages and disadvantages of various purification methods for intracellular or extracellular proteins, the most effective and widely used genetically engineered affinity tags, solubility-enhancing tags, and specific proteases for removal of nontarget sequences. Affinity chromatography (AC), like Protein A or G resins for the recovery of antibodies or Fc fusion proteins or immobilized metals for the recovery of histidine-tagged proteins, will be discussed along with other conventional chromatography techniques: ion exchange (IEC), hydrophobic exchange (HEC), mixed mode (MMC), size exclusion (SEC), and ultrafiltration (UF) systems. How to select and combine these different technologies for the purification of any given protein and the minimal criteria for QC characterization of the purity, homogeneity, identity, and integrity of the final product will be presented.

Size-dependent activity of carbon dots for photocatalytic H2 generation in combination with a molecular Ni cocatalyst

Carbon dots (CDs) are low-cost light-absorbers in photocatalytic multicomponent systems, but their wide size distribution has hampered rational design and the identification of the factors that lead to their best performance. To address this challenge, we report herein the use of gel filtration size exclusion chromatography to separate amorphous, graphitic, and graphitic N-doped CDs depending on their lateral size to study the effect of their size on photocatalytic H2 evolution with a DuBois-type Ni cocatalyst. Transmission electron microscopy and dynamic light scattering confirm the size-dependent separation of the CDs, whereas UV-vis and fluorescence spectroscopy of the more monodisperse fractions show a distinct response which computational modelling attributes to a complex interplay between CD size and optical properties. A size-dependent effect on the photocatalytic H2 evolution performance of the CDs in combination with a molecular Ni cocatalyst is demonstrated with a maximum activity at approximately 2-3 nm CD diameter. Overall, size separation leads to a two-fold increase in the specific photocatalytic activity for H2 evolution using the monodisperse CDs compared to the as synthesized polydisperse samples, highlighting the size-dependent effect on photocatalytic performance.

Application of chromatography in purification and structural analysis of natural polysaccharides: A review

Polysaccharides are widely distributed in natural sources from monocytic microorganisms to higher animals, and are found in a variety of biological activities in recent decades. Natural polysaccharides have the characteristics of large molecular weight, diverse composition, and complex structure, so their purification and structural analysis are difficult issues in research. Chromatography as a powerful separation technique, plays an irreplaceable role in the separation and structural analysis of natural polysaccharides, especially in the purification of polysaccharides, the separation of hydrolysates, and the analysis of monosaccharide composition. The separation mechanisms and application of different chromatographic methods in the studies of polysaccharides were summarized in this review. Moreover, the advantages and drawbacks of various chromatography methods were discussed as well.

Purification processes of polymeric nanoparticles: How to improve their clinical translation?

Polymeric nanoparticles, as revolutionary nanomedicines, have offered a new class of diagnostic and therapeutic solutions for a multitude of diseases. With its immense potential, the world witnesses the new age of nanotechnology after the COVID-19 vaccines were developed based on nanotechnology. Even though there are countless benchtop research studies in the nanotechnology world, their integration into commercially available technologies is still restricted. The post-pandemic world demands a surge of research in the domain, which leaves us with the fundamental question: why is the clinical translation of therapeutic nanoparticles so restricted? Complications in nanomedicine purification, among other things, are to blame for the lack of transference. Polymeric nanoparticles, owing to their ease of manufacture, biocompatibility, and enhanced efficiency, are one of the more explored domains in organic-based nanomedicines. Purification of nanoparticles can be challenging and necessitates tailoring the available methods in accordance with the polymeric nanoparticle and impurities involved. Though a number of techniques have been described, there are no available guidelines that help in selecting the method to better suit our requirements. We encountered this difficulty while compiling articles for this review and looking for methods to purify polymeric nanoparticles. The currently accessible bibliography for purification techniques only provides approaches for a specific type of nanomaterial or sometimes even procedures for bulk materials, that are not fully relevant to nanoparticles. In our research, we tried to summarize the available purification techniques using the approach of A.F. Armington. We divided the purification systems into two major classes, namely: phase separation-based techniques (based on the physical differences between the phases) and matter exchange-based techniques (centered on physicochemical induced transfer of materials and compounds). The phase separation methods are based on either using nanoparticle size differences to retain them on a physical barrier (filtration techniques) or using their densities to segregate them (centrifugation techniques). The matter exchange separation methods rely on either transferring the molecules or impurities across a barrier using simple physicochemical phenomena, like the concentration gradients (dialysis method) or partition coefficients (extraction technique). After describing the methods in detail, we highlight their advantages and limitations, mainly focusing on preformed polymer-based nanoparticles. Tailoring a purification strategy takes into account the nanoparticle structure and its integrity, the method selected should be suited for preserving the integrity of the particles, in addition to conforming to the economical, material and productivity considerations. In the meantime, we advocate the use of a harmonized international regulatory framework to define the adequate physicochemical and biological characterization of nanomedicines. An appropriate purification strategy serves as the backbone to achieving desired characteristics, in addition to reducing variability. As a result, the present review aspires to serve as a comprehensive guide for researchers, who are new to the domain, as well as a synopsis of purification strategies and analytical characterization methods used in preclinical studies.

Structural and functional analyses of Pcal_0917, an α-glucosidase from hyperthermophilic archaeon Pyrobaculum calidifontis

Genome analysis of Pyrobaculum calidifontis revealed the presence of α-glucosidase (Pcal_0917) gene. Structural analysis affirmed the presence of signature sequences of Type II α-glucosidases in Pcal_0917. We have heterologously expressed the gene and produced recombinant Pcal_0917 in Escherichia coli. Biochemical characteristics of the recombinant enzyme resembled to that of Type I α-glucosidases, instead of Type II. Recombinant Pcal_0917 existed in a tetrameric form in solution and displayed highest activity at 95 °C and pH 6.0, independent of any metal ions. A short heat-treatment at 90 °C resulted in a 35 % increase in enzyme activity. A slight structural shift was observed by CD spectrometry at this temperature. Half-life of the enzyme was >7 h at 90 °C. Pcal_0917 exhibited apparent V_max values of 1190 ± 5 and 3.9 ± 0.1 U/mg against p-nitrophenyl α-D-glucopyranoside and maltose, respectively. To the best of our knowledge, Pcal_0917 displayed the highest ever reported p-nitrophenyl α-D-glucopyranosidase activity among the characterized counterparts. Moreover, Pcal_0917 displayed transglycosylation activity in addition to α-glucosidase activity. Furthermore, in combination with α-amylase, Pcal_0917 was capable of producing glucose syrup from starch with >40 % glucose content. These properties make Pcal_0917 a potential candidate for starch hydrolyzing industry.

Soluble laticifer proteins from Calotropis procera as an effective candidates for antimicrobial therapeutics

Calotropis procera is a latex-producing plant with plenty of pharmacologically active compounds. The principal motivation behind this study was to separate and characterize laticifer proteins to check their antimicrobial potential. Laticifer proteins were separated by gel filtration chromatography (GFC) and investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The SDS-PAGE assay detected proteins of molecular weights of 10 to 30 kDa but most of them were in the range of 25 to 30 kDa. The soluble laticifer proteins (SLPs) were tested against Gram-positive bacteria i.e., Streptococcus pyogenes and Staphylococcus aureus whereas Escherichia coli and Pseudomonas aeruginosa were tested as Gram-negative bacteria, we determined a profound anti-bacterial activity of these proteins. In addition, SLPs were also investigated against Candida albicans via the agar disc diffusion method which also showed significant anti-fungal activity. SLP exhibited antibacterial activity against P. aeruginosa, E. coli, and S. aureus with a minimum inhibitory concentration (MIC) of 2.5 mg/mL for each, while MIC was found at 0.625 mg/mL for S. pyogenes and 1.25 mg/mL for C. albicans. Moreover, enzymatic activity evaluation of SLP showed the proteolytic nature of these proteins, and this proteolytic activity was greatly enhanced after reduction which might be due to the presence of cysteine residues in the protein structure. The activity of the SLPs obtained from the latex of C. procera can be associated with the involvement of enzymes either proteases or, protease inhibitors and/or peptides.

The Impact of Processing and Extraction Methods on the Allergenicity of Targeted Protein Quantification as Well as Bioactive Peptides Derived from Egg

This review article discusses advanced extraction methods to enhance the functionality of egg-derived peptides while reducing their allergenicity. While eggs are considered a nutrient-dense food, some proteins can cause allergic reactions in susceptible individuals. Therefore, various methods have been developed to reduce the allergenicity of egg-derived proteins, such as enzymatic hydrolysis, heat treatment, and glycosylation. In addition to reducing allergenicity, advanced extraction methods can enhance the functionality of egg-derived peptides. Techniques such as membrane separation, chromatography, and electrodialysis can isolate and purify specific egg-derived peptides with desired functional properties, improving their bioactivity. Further, enzymatic hydrolysis can also break down polypeptide sequences and produce bioactive peptides with various health benefits. While liquid chromatography is the most commonly used method to obtain individual proteins for developing novel food products, several challenges are associated with optimizing extraction conditions to maximize functionality and allergenicity reduction. The article also highlights the challenges and future perspectives, including optimizing extraction conditions to maximize functionality and allergenicity reduction. The review concludes by highlighting the potential for future research in this area to improve the safety and efficacy of egg-derived peptides more broadly.

Significant elevations of serum amylase caused by macroamylase: Case reports and detection possibilities

BACKGROUND

The presence of isolated elevated serum amylase levels can be caused by high molecular mass complexes. We describe 13 cases of hyperamylasemia detected in adult patients without clinical symptoms of a pancreatic disorder. Five of them were thoroughly examined using different tools for the detection of macrocomplexes.

METHODS

We performed both screening and more advanced methods of macroamylase detection, including polyethylene glycol precipitation, sample storage at 4°C and separation by gel filtration.

RESULTS

The presence of macroamylase in the suspected samples was confirmed by the methods described, except for the sample storage at 4°C. In this method, the enzyme activity did not decrease. The polyethylene glycol precipitation activity (% PPA) averaged 89.1% for amylase, whereas the control samples averaged 30.7%. Gel filtration chromatography confirmed an IgA macroamylase peak in three samples and an IgG macroamylase peak in two samples.

CONCLUSION

The presence of macroamylase should be suspected whenever the clinical history and condition of the patient do not match the measured enzyme value to avoid diagnostic errors and unnecessary invasive examinations. The presence of macrocomplexes is considered a benign process that may occur in apparently healthy individuals. Cooperation between clinicians and laboratory staff is necessary.

A Prolyl Endopeptidase from Flammulina velutipes Degrades Celiac Disease-Inducing Peptides in Grain Flour Samples

Celiac disease (CD) is an inflammatory disorder of the small intestine. Gluten peptides are supposed to be responsible for the reaction, the best-researched of which is the so-called ‘33-mer’. Analogous peptides in secalins (rye) and hordeins (barley) have been described. This study presents the degradation of gliadins, glutenins, hordeins and secalins purified from the respective flours using a prolyl endopeptidase from the Basidiomycete Flammulina velutipes (FvpP). The flour fractions were incubated with the enzyme, and the cleavage sites were determined using high-resolution nLC-qTOF-MS/MS. For the wheat samples, eight cleavage sites in the 33-mer peptide were shown, and all of the six described epitopes were successfully cleaved. For the commercially available prolyl-specific endopeptidase from Aspergillus niger (An-Pep), which was used as a control, only two cleavage sites that cleaved three of the six epitopes were identified. For the secalins, four prolyl-specific cleavage sites in the CD-active peptide QPFPQPQQPIPQ were found for the FvpP but none for the An-Pep. The CD-active peptide QPFPQPEQPFPW in C-hordein was cleaved at three prolyl-specific positions by the FvpP. The study proves the usability of FvpP to degrade CD-inducing peptides in real-grain flour samples and indicates its higher effectiveness compared with An-Pep. A clinical study would be required to assess the therapeutic or preventive potential of FvpP for CD.

Technological interventions in improving the functionality of proteins during processing of meat analogs

Meat analogs have opened a new horizon of opportunities for developing a sustainable alternative for meat and meat products. Proteins are an integral part of meat analogs and their functionalities have been extensively studied to mimic meat-like appearance and texture. Proteins have a vital role in imparting texture, nutritive value, and organoleptic attributes to meat analogs. Processing of suitable proteins from vegetable, mycoproteins, algal, and single-cell protein sources remains a challenge and several technological interventions ranging from the isolation of proteins to the processing of products are required. The present paper reviews and discusses in detail various proteins (soy proteins, wheat gluten, zein, algal proteins, mycoproteins, pulses, potato, oilseeds, pseudo-cereals, and grass) and their suitability for meat analog production. The review also discusses other associated aspects such as processing interventions that can be adapted to improve the functional and textural attributes of proteins in the processing of meat analogs (extrusion, spinning, Couette shear cell, additive manufacturing/3D printing, and freeze structuring). '.

Two-Dimensional Blue Native/SDS Polyacrylamide Gel Electrophoresis for Analysis of Brazilian Bothrops Snake Venoms

Viperidae snakes are the most important agents of snakebites in Brazil. The protein composition of snake venoms has been frequently analyzed by means of electrophoretic techniques, but the interaction of proteins in venoms has barely been addressed. An electrophoretic technique that has gained prominence to study this type of interaction is blue native polyacrylamide gel electrophoresis (BN-PAGE), which allows for the high-resolution separation of proteins in their native form. These protein complexes can be further discriminated by a second-dimension gel electrophoresis (SDS-PAGE) from lanes cut from BN-PAGE. Once there is no study on the use of bidimensional BN/SDS-PAGE with snake venoms, this study initially standardized the BN/SDS-PAGE technique in order to evaluate protein interactions in Bothrops atrox, Bothrops erythromelas, and Bothrops jararaca snake venoms. Results of BN/SDS-PAGE showed that native protein complexes were present, and that snake venom metalloproteinases and venom serine proteinases maintained their enzymatic activity after BN/SDS-PAGE. C-type lectin-like proteins were identified by Western blotting. Therefore, bidimensional BN/SDS-PAGE proved to be an easy, practical, and efficient method for separating functional venom proteins according to their assemblage in complexes, as well as to analyze their biological activities in further details.

Functional Properties and Extraction Techniques of Chicken Egg White Proteins

Chicken egg whites contain hundreds of proteins, and are widely used in the food, biological and pharmaceutical industries. It is highly significant to study the separation and purification of egg white proteins. This review first describes the structures and functional properties of several major active proteins in egg whites, including ovalbumin, ovotransferrin, ovomucoid, lysozyme, ovomucin, ovomacroglobulin and avidin. Then, the common techniques (including precipitation, chromatography and membrane separation) and some novel approaches (including electrophoresis, membrane chromatography, aqueous two-phase system and molecular imprinting technology) for the separation and purification of egg white proteins broadly reported in the current research are introduced. In addition, several co-purification methods for simultaneous separation of multiple proteins from egg whites have been developed to improve raw material utilization and reduce costs. In this paper, the reported techniques in the last decade for the separation and purification of chicken egg white proteins are reviewed, discussed and prospected, aiming to provide a reference for further research on egg proteins in the future.

Recent advances in bioactive peptides from cereal-derived Foodstuffs

Cereal-derived proteins account for a major part of human dietary protein consumption. Natural bioactive peptides (NBPs) from these proteins involve a variety of physiological activities and play an important role in the promotion of human health. This review focuses on the characteristics of NBPs obtained from cereals, and the commonly used methods for preparation, separation, purification, and identification. We also discussed the biological functions of cereal-derived NBPs (CNBPs), including the activities of antioxidant, immunomodulatory, antimicrobial, and regulation of hyperglycaemia and hypertension. The paper summarised the latest progress in the research and application of CNBPs and analysed the prospects for the development and application of several protein by-products, providing an important way to improve the added value of protein by-products in cereal processing.

Separation and Analytical Techniques Used in Snake Venomics: A Review Article

The deleterious consequences of snake envenomation are due to the extreme protein complexity of snake venoms. Therefore, the identification of their components is crucial for understanding the clinical manifestations of envenomation pathophysiology and for the development of effective antivenoms. In addition, snake venoms are considered as libraries of bioactive molecules that can be used to develop innovative drugs. Numerous separation and analytical techniques are combined to study snake venom composition including chromatographic techniques such as size exclusion and RP-HPLC and electrophoretic techniques. Herein, we present in detail these existing techniques and their applications in snake venom research. In the first part, we discuss the different possible technical combinations that could be used to isolate and purify SV proteins using what is known as bioassay-guided fractionation. In the second part, we describe four different proteomic strategies that could be applied for venomics studies to evaluate whole venom composition, including the mostly used technique: RP-HPLC. Eventually, we show that to date, there is no standard technique used for the separation of all snake venoms. Thus, different combinations might be developed, taking into consideration the main objective of the study, the available resources, and the properties of the target molecules to be isolated.

Recent advances on protein separation and purification methods

Protein, as the material basis of vita, is the crucial undertaker of life activities, which constitutes the framework and main substance of human tissues and organs, and takes part in various forms of life activities in organisms. Separating proteins from biomaterials and studying their structures and functions are of great significance for understanding the law of life activities and clarifying the essence of life phenomena. Therefore, scientists have proposed the new concept of proteomics, in which protein separation technology plays a momentous role. It has been diffusely used in the food industry, agricultural biological research, drug development, disease mechanism, plant stress mechanism, and marine environment research. In this paper, combined with the recent research situation, the progress of protein separation technology was reviewed from the aspects of extraction, precipitation, membrane separation, chromatography, electrophoresis, molecular imprinting, microfluidic chip and so on.

Differences in peptide generation following in vitro gastrointestinal digestion of yogurt and milk from cow, sheep and goat

Fermentation of milk is commonly used throughout the world to produce a variety of foods with different health benefits. We hypothesised that due to differences in physicochemical properties and protein sequences among milk from different species and their fermented yogurt samples, their protein digestion and resulting peptide profiles would differ. Cow, goat and sheep milk and yogurt were compared at designated timepoints throughout in vitro gastric and intestinal digestion for differences in peptide profiles and peptide bioactivities. The results showed that most proteins in all milk and yogurt samples were digested within the early phase of gastric digestion. β-Lg and β-CN were digested faster in yogurt than milk, which was most evident for sheep products. Regardless of species, in vitro gastric and intestinal digestion released a higher concentration of specific peptides, particularly anti-hypertensives, from yogurt compared with their milk counterparts.

The use of size-exclusion chromatography in the isolation of supercoiled minicircle DNA from Escherichia coli lysate

Minicircle DNA (mcDNA) is the new cutting-edge technology which researchers have been exploring for gene therapy and DNA vaccination. Although it presents enormous advantages in comparison to conventional plasmid DNA regarding bioactivity and safety, its challenging isolation from parental plasmid and miniplasmid has been setting back its launching in biomedical sciences. In this work, it is demonstrated the use of a simple size exclusion chromatographic method for the isolation of supercoiled mcDNA. Sephacryl S-1000 SF matrix was explored under different conditions (flow, peak fractionation volume and sample loading) to achieve the best performance and retrieve a mcDNA sample devoid of other bacterial contaminants or plasmid species resultant from the recombination process. This isolation methodology resulted in 66.7% of mcDNA recovery with 98.1% of purity. In addition, to show the robustness of the method, the potential of using this matrix for the isolation of a larger mcDNA was also evaluated. Upon adjusting the flow or the column volume, the larger mcDNA molecule was also successfully isolated. Overall, a simple and effective strategy has been established for the isolation of supercoiled mcDNA, underlining the potential of size exclusion chromatography in mcDNA separation.

Proteomic Analysis and Immuno-Profiling of Eastern India Russell's Viper ( Daboia russelii) Venom: Correlation between RVV Composition and Clinical Manifestations Post RV Bite

The proteomes of Russell's viper venom (RVV) from Burdwan (RVV B) and Nadia (RVV N), the two districts of West Bengal, eastern India (EI), were investigated by gel-filtration chromatography (GFC) followed by tandem mass spectrometry of tryptic fragments of the fractions. A total of 73 and 69 proteins belonging to 15 snake venom protein families were identified in RVV B and RVV N, respectively, by MS/MS search against Viperidae (taxid 8689) protein entries of the nonredundant NCBI database. The minor differences in venom composition of both the EI RV were established unequivocally by their biochemical and pharmacological properties and by SDS-PAGE, gel filtration chromatography, and LC-MS/MS analyses. The composition of EI RVVs was well correlated with published reports on the pathophysiology of RV-envenomed patients from this part of the country. Venom-antivenom cross-reactivity determined by ELISA, Western blotting, and antivenomics approaches demonstrated poor recognition of low molecular mass (<20 kDa) RVV proteins by commercial polyvalent antivenoms, which was substantiated by neutralization of RVV enzymes by antivenom.