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Öğe Biofortified Whey/Deglycosylated Whey and Chickpea Protein Matrices: Functional Enrichment by Black Mulberry Polyphenols(Springer, 2022) Ozleyen, Adem; Cinar, Zeynep Ozlem; Karav, Sercan; Bayraktar, Ayse; Arslan, Aysenur; Kayili, H. Mehmet; Salih, BekirMorus nigra L. (black mulberry-BM) is a promising nutraceutical fruit containing biologically active polyphenols like anthocyanins, proanthocyanidins, catechins, and stilbenes, with well-established anti-inflammatory, antidiabetic, anti-obesity, and anticancer biofunctions. However, these health-promoting properties in raw fruit are greatly masked due to the presence of soluble and insoluble carbohydrates in excess amounts restricting daily intake of the required dose to achieve targeted effects. In the current study, different protein sources (defatted whey and chickpea flours) were optimized through different conditions to capture polyphenols from BM juice while diminishing its glucose content. To optimize polyphenol-protein interactions, various pHs (3.7, 4.2, and 4.7), matrix concentrations (20, 50, and 80 g protein/L), and incubation times (5, 20, and 45 min) were tested. In the present work, optimized BM polyphenol enriched whey matrix inhibited pro-inflammatory mediators and promoted Nrf-2 dependent cytoprotective enzyme expressions in lipopolysaccharide (LPS) induced macrophages at low doses. In addition, whey proteins were also subjected to an enzymatic deglycosylation process by using recently identified EndoBI-1 enzyme for the specific cleavage of N-glycan core in all glycan types including high mannoses, hybrids as well as complex glycans found on defatted whey proteins. After this process, the polyphenol sorption capacity of deglycosylated whey proteins was found to be significantly higher (37%) than the capacity of non-treated normal whey protein under optimized conditions. In conclusion, deglycosylation of protein matrices could be a novel strategy for efficient sorption/concentration of polyphenols from fruits and vegetables, however, more detailed studies are needed to understand this effect.Öğe Immobilization of a Bifidobacterial Endo-ss-N-Acetylglucosaminidase to Generate Bioactive Compounds for Food Industry(Frontiers Media Sa, 2022) Pekdemir, Burcu; Duman, Hatice; Arslan, Aysenur; Kaplan, Merve; Karyelioglu, Melda; ozer, Tolgahan; Kayili, Haci MehmetConjugated N-glycans are considered next-generation bioactive prebiotic compounds due to their selective stimulation of beneficial microbes. These compounds are glycosidically attached to proteins through N-acetylglucosamines via specific asparagine residue (AsN-X-Ser/Thr). Certain bacteria such as Bifidobacterium longum subspecies infantis (B. infantis) have been shown to be capable of utilizing conjugated N-glycans, owing to their specialized genomic abilities. B. infantis possess a unique enzyme, Endo-ss-N-acetylglucosaminidase (EndoBI-1), which cleaves all types of conjugated N-glycans from glycoproteins. In this study, recombinantly cloned EndoBI-1 enzyme activity was investigated using various immobilization methods: 1) adsorption, 2) entrapment-based alginate immobilization, 3) SulfoLink-, and 4) AminoLink-based covalent bonding immobilization techniques were compared to develop the optimum application of EndoBI-1 to food processes. The yield of enzyme immobilization and the activity of each immobilized enzyme by different approaches were investigated. The N-glycans released from lactoperoxidase (LPO) using different immobilized enzyme forms were characterized using MALDI-TOF mass spectrometry (MS). As expected, regardless of the techniques, the enzyme activity decreased after the immobilization methods. The enzyme activity of adsorption and entrapment-based alginate immobilization was found to be 71.55% +/- 0.6 and 20.32% +/- 3.18, respectively, whereas the activity of AminoLink- and SulfoLink-based covalent bonding immobilization was found to be 58.05 +/- 1.98 and 47.49% +/- 0.30 compared to the free form of the enzyme, respectively. However, extended incubation time recovery achieved activity similar to that of the free form. More importantly, each immobilization method resulted in the same glycan profile containing 11 different N-glycan structures from a model glycoprotein LPO based on MALDI-TOF MS analysis. The glycan data analysis suggests that immobilization of EndoBI-1 is not affecting the enzyme specificity, which enables full glycan release without a limitation. Hence, different immobilization methods investigated in this study can be chosen for effective enzyme immobilization to obtain bioactive glycans. These findings highlight that further optimization of these methods can be a promising approach for future processing scale-up and commercialization of EndoBI-1 and similar enzymes.Öğe Potential Applications of Endo-?-N-Acetylglucosaminidases From Bifidobacterium longum Subspecies infantis in Designing Value-Added, Next-Generation Infant Formulas(Frontiers Media Sa, 2021) Duman, Hatice; Kaplan, Merve; Arslan, Aysenur; Sahutoglu, Arif Sercan; Kayili, Haci Mehmet; Frese, Steven A.; Karav, SercanHuman milk is the optimal source of infant nutrition. Among many other health benefits, human milk can stimulate the development of a Bifidobacterium-rich microbiome through human milk oligosaccharides (HMOs). In recent years, the development of novel formulas has placed particular focus on incorporating some of the beneficial functional properties of human milk. These include adding specific glycans aimed to selectively stimulate the growth of Bifidobacterium. However, the bifidogenicity of human milk remains unparalleled. Dietary N-glycans are carbohydrate structures conjugated to a wide variety of glycoproteins. These glycans have a remarkable structural similarity to HMOs and, when released, show a strong bifidogenic effect. This review discusses the biocatalytic potential of the endo-beta-N-acetylglucosaminidase enzyme (EndoBI-1) from Bifidobacterium longum subspecies infantis (B. infantis), in releasing N-glycans inherently present in infant formula as means to increase the bifidogenicity of infant formula. Finally, the potential implications for protein deglycosylation with EndoBI-1 in the development of value added, next-generation formulas are discussed from a technical perspective.Öğe Recombinant Production of Bifidobacterial Endoglycosidases for N-glycan Release(Journal Of Visualized Experiments, 2021) Sucu, Berfin; Bayraktar, Ayse; Duman, Hatice; Arslan, Aysenur; Kaplan, Merve; Karyelioglu, Melda; Ntelitze, EdaProtein glycosylation is a diverse and common post-translational modification that has been associated with many important roles such as protein function, including protein folding, stability, enzymatic protection, and biological recognition. N-glycans attached to glycoproteins (such as lactoferrin, lactadherin, and immunoglobulins) cannot be digested by the host and reach the large intestine, where they are consumed by certain beneficial microbes. Therefore, they are considered nextgeneration prebiotic compounds that can selectively stimulate the gut microbiome's beneficial microorganisms. However, the isolation of these new classes of prebiotics requires novel enzymes. Here, we describe the recombinant production of novel glycosidases from different Bifidobacteria strains (isolated from infants, rabbits, chicken, and bumblebee) for improved N-glycan isolation from glycoproteins. The method presented in this study includes the following steps: molecular cloning of Bifidobacterial genes by an in vivo recombinational cloning strategy, control of transformation success, protein induction, and protein purification.Öğe Ten-year single center experience in hepatotoxicity due to mushroom poisoning(Elsevier, 2022) Sarikaya, Ozan; Turan, Ilker; Gunsar, Fulya; Arslan, Aysenur; Danis, Nilay; Celik, Ferit; Ersoz, Galip[No abstract available]
