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Exopolysaccharide Production from Marine Bacteria and Its Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Prashakha J. Shukla, Shivang B. Vhora, Ankita G. Murnal, Unnati B. Yagnik, Maheshwari Patadiya
EPSs have been used widely for medical purposes because of their unique and superior physical properties relative to other biomaterials. They have been used for diverse applications in biomedical field as ophthalmology, tissue engineering, antitumor, immune-stimulant activities, fibrinolytic agent, implantation of medical devices and artificial organs, prostheses, dentistry, bone repair and more (Shih, 2010). They are significantly applied in the field of glycochemistry and glycobiology in the form of glycosaminoglycans (GAGs) and are also being extensively used for the design and preparation of therapeutic drugs (Delbarre-Ladrat et al., 2014). EPSs from marine thermophilic bacilli were used for inducing a Th1 cytokine profile in humans (Arena et al., 2004). EPSs is also applied in antimetastatic treatment as reported by Heymann et al. (2016). Other reports for medicinal uses assigned to EPSs are antiproliferative, anticoagulant, antiviral and antiangiogenic activities (Arena et al., 2009; Llamas et al., 2010). EPSs from the genus Bacillus have been reported to possess strongest fibrinolytic activity (Lee and Kim, 2012).
The Development of Improved Therapeutics through a Glycan- “Designer” Approach
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
The bioinformatics for glycan prediction, analysis, and visualization is a growing area of extensive research. Using both prediction software and available databases with already described glycans, it is possible to start with in silico design of glycomodifications without the need for labor-intensive methods. However, the high throughput prediction workflow is a major challenge since the glycosylation is a complexed, condition-dependent PTM controlled by gene expression responsible for glycan synthesis. Therefore, to decipher glycobiology of a cell one needs to investigate gene expression, glycan structure, glycan binding receptors and their role in a cell signaling and regulation. For this purpose, the field of glycobiology developed a range of open databases and repositories.
Precision medicine for colorectal cancer
Published in Debmalya Barh, Precision Medicine in Cancers and Non-Communicable Diseases, 2018
Candan Hızel, Şükrü Tüzmen, Arsalan Amirfallah, Gizem Çalıbaşı Koçal, Duygu Abbasoğlu, Haluk Onat, Yeşim Yıldırım, Yasemin Baskın
Although carbohydrates are considered to be the most abundant macromolecules in nature, they have been underestimated and considered less functionally significant than nucleic acids and proteins. Due to their large and complex heterogeneity, carbohydrates and glycoconjugates have been difficult to isolate from their natural sources owing to the lack of efficient technologies. Consequently, this diminished the recognition of their significance in the most basic biological practices, leading to the lack of exploration of the carbohydrates in the biological arena. Nevertheless, in the past few decades complex carbohydrate expression has been acknowledged to be crucial in the establishment of living networks, including cellular signaling, cellular differentiation, and the immune system (Adamczyk et al., 2012; Drake, 2015; Siobhan et al., 2015). The recognition of this structure and functional connection of carbohydrates facilitated chemical and biological protocols to unveil new areas in molecular biology, coining the term glycobiology in the early 1980s. State-of-the-art protocols have thrived ever since, leading to the examination of “glycomaterials” for their glycan function (Adamczyk et al., 2012; Drake, 2015; Siobhan et al., 2015). The normal activity of glycosylation is interfered during cancer cell formation (Kim and Varki, 1997; Kannagi et al., 2004). These alterations in the tumor cells lead to the restructuring of the cell surface glycans of the transformed tumors regulating metastatic potential of the cancer cells (Shriver et al., 2004). Additionally, parallel to the alterations in the glycosylation status of the cancer cell surfaces, gene expression profiles of the carbohydrate binding proteins get modified during this neoplastic transformation causing a comprehensive alteration between the glycans and their associated receptors (Kannagi et al., 2004; Shriver et al., 2004). The mechanism via which glycosylation modification triggers cancer cell metastasis and invasion are yet to be determined, but the functions of the particular cell surface bound glycoproteins and their carbohydrate motifs have been recently identified (Dall'Olio et al., 2012; Geng et al., 2012). Due to the recent developments in the glycoanalytical methodologies, a better comprehension of the carbohydrate connection to the cell surface lipids and proteins has emerged (Siobhan et al., 2015). Learning how the glycan determinants work on cancer-associated proteins helped to unveil a new level of complexity, facilitating better comprehension of how neoplasia changes the normal process in cells. Additionally, the orchestration of glycan determinants on cancer can have connections with cancer cell metastasis, proliferation, survival, and immune escape. This extensive knowledge about the cancer glycome has implications to be very effective in the cancer field (Siobhan et al., 2015). However, much still remains to be unveiled pertaining to the functional interactions of cell surface glycans with the regulation of the metastatic potential of the cancer cells. Thorough knowledge of carbohydrate remodeling in cancer will require complete profiling of glycosylation patterns in the tumor microenvironment (Siobhan et al., 2015).
Relevance of glycans in the interaction between T lymphocyte and the antigen presenting cell
Published in International Reviews of Immunology, 2021
Wilton Gómez-Henao, Eda Patricia Tenorio, Francisco Raúl Chávez Sanchez, Miguel Cuéllar Mendoza, Ricardo Lascurain Ledezma, Edgar Zenteno
Classically, glycosylation analysis in biological systems has been performed using lectins within techniques like flow cytometry, microscopy, microarrays, and lectin-blot, while high-performance chromatography and mass spectrometry have made it possible to elucidate with great precision the structure and molecular sequence of these glycans [21–23]. Understanding the functional role of glycosylation´s in biological contexts has traditionally been approached with specific inhibitors [24, 25]. However, these molecules affect glycosylation on all proteins that are post-translationally modified by each inhibited glycosylation, making this strategy quite unspecific for the study of the role of glycosylation on individual proteins. Recently, the use of antibody-glycosidase conjugates that selectively eliminate glycans present on a target protein without affecting glycosylation on other glycoconjugates has been reported. This will provide a new perspective in the study of glycoproteins and their potential therapeutic use in different diseases like cancer or autoimmune diseases [26]. The effort dedicated understand the structural and functional role of glycans has led to the creation of databases that allow a thorough study of glycomes, a branch of glycobiology known as glycomics [27].
Glycosylation and its implications in breast cancer
Published in Expert Review of Proteomics, 2019
Danielle A. Scott, Richard R. Drake
Glycosylation is a term used to describe the biosynthetic enzymatic process that involves the sequential removal and addition of individual carbohydrates to proteins and lipids [49]. For glycoproteins, the attached glycans are classified as either N-linked (Asn) or O-linked (Ser/Thr) based on the amino acid residue to which they are attached. N-linked glycosylation of newly synthesized proteins occurs co-translationally in the endoplasmic reticulum. N-linked glycans are further processed by a highly regulated sequential series of glycosidases and glycosyltransferases in the ER and Golgi apparatus. Individual glycosyltransferases may exhibit overlapping specificities in some instances [50,51]. These enzymes typically transfer single sugar residues from nucleotide-sugar donors to protein and sugar acceptors, which results in glycan elongation forming a vast array of glycan structures [52]. N-linked glycans most commonly contain mannose, galactose, N-acetylglucosamine, fucose, and sialic acid sugars, and less commonly N-acetylgalactosamine and glucose. O-linked glycans are predominantly comprised of shorter structures with N-acetylgluosamine, galactose, N-acetylgalactosamine, sialic acid, and fucose. The presence of sulfate and phosphate groups are also possible. Examples of glycoproteins with N-linked and O-linked modifications and carbohydrate antigens associated with cancer are shown in Figure 2 [49]. For a summary of the complex biosynthetic and processing reactions associated with N-linked and O-linked glycans, see the freely available on-line reference Essentials in Glycobiology [53].
Human disease glycomics: technology advances enabling protein glycosylation analysis – part 2
Published in Expert Review of Proteomics, 2018
Arun V Everest-Dass, Edward S X Moh, Christopher Ashwood, Abdulrahman M M Shathili, Nicolle H Packer
The simultaneous characterization of both the glycan (substructure) moieties and their protein carriers is also an added advantage especially in the discovery of biomarkers for diseases. This brings an added dimension and can increase the sensitivity associated with several disease biomarkers where both a protein and associated glycosylation change can be used to reduce the false positives. Similarly, a systems-glycobiology approach including the genomics, proteomics, epigenomics, transcriptomics, and metabolomics, all of which are involved in the cellular glycosylation machinery, will benefit the understanding and monitoring of disease mechanisms.