Publications by authors named "Ha Hyung Kim"

Chinese hamster ovary (CHO)-K1 cells are widely used in biomedical research relevant to cancer, toxicity screening, and viruses, as well as in the production of recombinant proteins for biopharmaceuticals. In this study, liquid chromatography (LC)-electrospray ionization (ESI)-higher energy collisional dissociation (HCD)-tandem mass spectrometry (MS/MS) was used to characterize the surface and lysate N-glycans of CHO-K1 cells and analyze their structures. The relative quantity (%) of each N-glycan and absolute quantity (pmol) of total N-glycans were also obtained.

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Phosvitin (PV), a highly phosphorylated protein found in chicken egg yolk, possesses multiple bioactivities (including anti-aging and anticancer) and functional properties (including emulsifier and metal-binding capacities). The carbohydrate moiety attached to PV has been reported, but its N-glycan structure is unknown. In this study, we performed structural and quantitative analyses of N-glycans from PV using liquid chromatography-tandem mass spectrometry (MS/MS).

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Article Synopsis
  • MIN6, a mouse pancreatic beta cell line, is crucial for diabetes research, focusing on the role of N-glycoproteins in insulin secretion metabolism.
  • The study identified and analyzed 50 different N-glycans in MIN6 cell membranes using advanced mass spectrometry, highlighting their relative abundances and structural categories, including bisecting N-acetylglucosamine, core-fucosylated, and sialylated types.
  • Findings indicate that these N-glycan structures significantly influence cell adhesion and interactions, potentially enhancing insulin secretion efficiency in beta cells, with notable differences compared to human islets.
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Host N-glycans play an essential role in the attachment, invasion, and infection processes of viruses, including zoonotic infectious diseases. The similarity of N-glycans in the trachea and lungs of humans and pigs facilitates the cross-species transmission of influenza viruses through respiratory tracts. In this study, the structure and quantity of N-glycans in the plasma of humans, pigs, and chickens were analyzed using liquid chromatography-quadrupole-Orbitrap-tandem mass spectrometry.

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Bovine intestinal alkaline phosphatase (biALP), a membrane-bound plasma metalloenzyme, maintains intestinal homeostasis, regulates duodenal surface pH, and protects against infections caused by pathogenic bacteria. The N-glycans of biALP regulate its enzymatic activity, protein folding, and thermostability, but their structures are not fully reported. In this study, the structures and quantities of the N-glycans of biALP were analyzed by liquid chromatography-electrospray ionization-high energy collision dissociation-tandem mass spectrometry.

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Interleukin-2 (IL-2), a cytokine with pleiotropic immune effects, was the first approved cancer immunotherapy agent. However, IL-2 is associated with systemic toxicity due to binding with its ligand IL-2Rα, such as vascular leakage syndrome, limiting its clinical applications. Despite efforts to extend the half-life of IL-2 and abolish IL-2Rα interactions, the risk of toxicity remains unresolved.

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Article Synopsis
  • - HAPLN1 is an extracellular matrix protein that helps stabilize connections between hyaluronan and proteoglycan, but its N-glycosylation (a type of carbohydrate modification) is not well understood.
  • - In this study, researchers used advanced techniques to identify 66 N-glycopeptides from HAPLN1 that had been expressed in CHO cells, finding significant differences in the types of N-glycans at two specific sites (Asn 6 and Asn 41).
  • - The findings suggest that the N-glycans at these sites serve different purposes: those at Asn 6 help protect the protein, while those at Asn 41 enhance its ability to interact
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Bovine testicular hyaluronidase (BTH), which accelerates the absorption and dispersion of drugs by decomposing hyaluronan in subcutaneous tissues, has been used in medical applications, including local anesthesia, ophthalmology, and dermatosurgery. The requirement of N-glycans for the activity of human hyaluronidase has been reported, and BTH has greater activity than human hyaluronidase. However, the N-glycan characteristics of BTH are unclear.

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Animal-derived hyaluronidase, which hydrolyzes the polysaccharide hyaluronic acid, has been used in medical applications despite its limited purity. Additionally, the N-glycan characterization of sheep testicular hyaluronidase (STH) and its structural role remain poorly understood. In this study, STH was purified from the commercially available STH preparation (containing at least 14 impurity proteins) using heparin-affinity chromatography followed by size exclusion chromatography.

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Chronic obstructive pulmonary disease (COPD) will be the third leading cause of death worldwide by 2030. One of its components, emphysema, has been defined as a lung disease that irreversibly damages the lungs' alveoli. Treatment is currently unavailable for emphysema symptoms and complete cure of the disease.

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Article Synopsis
  • - Recent advances in RNA delivery systems have enabled the creation of various RNA therapeutics like mRNA, miRNA, and ASOs, which are gaining traction in cancer research due to their design flexibility and rapid production.
  • - Targeting tumors is challenging because they often consist of diverse cancer cell populations; RNA-based therapies offer potential solutions in personalized medicine by addressing this heterogeneity.
  • - The review highlights the effectiveness of different RNA modalities in treating resistant tumors and suggests promising combinations of RNA therapies with cancer immunotherapy for enhanced outcomes.
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Sialylated -glycan isomers with α2-3 or α2-6 linkage(s) have distinctive roles in glycoproteins, but are difficult to distinguish. Wild-type (WT) and glycoengineered (mutant) therapeutic glycoproteins, cytotoxic T lymphocyte-associated antigen-4-immunoglobulin (CTLA4-Ig), were produced in Chinese hamster ovary cell lines; however, their linkage isomers have not been reported. In this study, -glycans of CTLA4-Igs were released, labeled with procainamide, and analyzed by liquid chromatography-tandem mass spectrometry (MS/MS) to identify and quantify sialylated -glycan linkage isomers.

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Background: N-glycans in glycoproteins can affect physicochemical properties of proteins; however, some reported N-glycan structures are inconsistent depending on the type of glycoprotein or the preparation methods.

Objective: To obtain consistent results for qualitative and quantitative analyses of N-glycans, N-glycans obtained by different preparation methods were compared for two types of mammalian glycoproteins.

Methods: N-glycans are released by peptide-N-glycosidase F (PF) or A (PA) from two model mammalian glycoproteins, bovine fetuin (with three glycosylation sites) and human IgG (with a single glycosylation site), and labeled with a fluorescent tag [2-aminobenzamide (AB) or procainamide (ProA)].

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Extensive bowel resection caused by various diseases that affect the intestines, such as Crohn's disease, volvulus, and cancer, leads to short bowel syndrome (SBS). Teduglutide is the only approved glucagon-like peptide-2 (GLP-2) drug for SBS; however, it requires daily administration. A novel GLP-2 analog with a prolonged duration of action to reduce dosing frequency and promote a greater efficacy may provide patients with a better quality of life.

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Congenital hyperinsulinism (CHI) is a rare genetic condition characterized by uncontrolled insulin secretion, resulting in hypoglycemia. Although glucagon has lately been regarded as a therapeutic option for CHI, its use is severely hampered by its poor solubility and stability at physiological pH, as well as its short duration of action. To address these constraints, we developed HM15136, a novel long-acting glucagon analog composed of a glucagon analog conjugated to the Fc fragment of human immunoglobulin G4 via a polyethylene glycol linker.

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Background: The identification of N-glycans in plant glycoproteins or plant-made pharmaceuticals is essential for understanding their structure, function, properties, immunogenicity, and allergenicity (induced by plant-specific core-fucosylation or xylosylation) in the applications of plant food, agriculture, and plant biotechnology. N-glycosidase A is widely used to release the Nglycans of plant glycoproteins because the core-fucosylated N-glycans of plant glycoproteins are hydrolyzed by N-glycosidase A but not by N-glycosidase F. However, the efficiency of Nglycosidase A activity in plant glycoproteins remains unclear.

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Sialylated and core-fucosylated N-glycans in human transferrin (HTF) are used as glycan biomarkers due to their increased or decreased characteristics in certain diseases. However, their absolute quantities remain unclear. In this study, N-glycans of HTF were identified by UPLC and LC-MS/MS using fluorescence tags [2-aminobenzamide (AB) and procainamide (ProA)] and columns [HILIC and anion exchange chromatography-HILIC (AXH)].

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Article Synopsis
  • The study focused on enhancing the production of CTLA4-Ig, a fusion protein important for immune response regulation, using genetically modified CHO cells to increase sialic acid levels via glycoengineering.
  • Researchers overexpressed genes responsible for glycan modifications, specifically N-acetylglucosaminyltransferases (GnT-IV and GnT-V) and α2,6-sialyltransferase, in CHO cells.
  • Results showed that co-overexpressing GnT-IV and α2,6-ST significantly increased the production of bi- and tri-sialylated glycans, which are beneficial for the therapeutic effectiveness of CTLA4-Ig.
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Bovine submaxillary mucin (BSM) is a natural polymer used in biomaterial applications for its viscoelasticity, lubricity, biocompatibility, and biodegradability. -glycans are important for mucin stability and function, but their structures have not been fully characterized, unlike that of -glycans. In this study, BSM -glycans were investigated using liquid chromatography-tandem mass spectrometry.

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FGF21 (Fibroblast Growth Factor 21), which is expressed in the liver, adipose tissue, and pancreas, has been widely known as a therapeutic candidate for metabolic diseases. Though FGF21 is crucial to glucose, lipid, and energy homeostasis, it is not straightforward to develop a new drug with FGF21 due to its short half-life in serum. Here, we derived a novel long-acting FGF21 (LAPS-FGF21), which is chemically conjugated to the human IgG4 Fc fragment for longer half-life in serum.

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We recently reported the biological evaluations of monovalent IAP antagonist 7 with good potency (MDA-MB-231, IC = 19 nM). In an effort to increase cellular activity and improve favorable drug-like properties, we newly designed and synthesized bivalent analogues based on quinazoline structure of 7. Optimization of cellular potency and CYP inhibition led to the identification of 27, which showed dramatic increase of over 100-fold (IC = 0.

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Whey, a by-product of cheese making, is a collection of several milk proteins and has functional and nutritional values. Whey protein concentrate (WPC) exhibits various functional effects by glycation. Studies to find sugar-binding sites in a protein having a functional effect are reported.

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Anemia is a frequent complication of chronic kidney disease (CKD) that causes an increase in morbidity and mortality and accelerates the rate of disease progression. Treatment with recombinant human erythropoietin (rhEPO) is a major breakthrough in the therapy of renal anemia. HM10760A, a long-acting EPO, has been developed as a treatment for anemia in CKD patients.

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Bovine submaxillary mucin (BSM) is a gel-forming glycoprotein polymer, and Ser/Thr-linked glycans (-glycans) are important in regulating BSM's viscoelasticity and polymerization. However, details of -glycosylation have not been reported. This study investigates the structural and quantitative characteristics of -glycans and identifies -glycosylation sites in BSM using liquid chromatography-tandem mass spectrometry.

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Recombinant human acid alpha-glucosidase (rhGAA) from Chinese hamster ovary cells is the only approved treatment for patients with Pompe disease. In this study, rhGAAs were produced in transgenic rice cell suspension cultures under eight different conditions; untreated, 5 μM of 2-fluoro-l-fucose (2-FF), 50 μM of 2-FF, 100 μM of 2-FF, 100 μM of 2-FF + 0.5% Pluronic F-68 (PF-68), 100 μM of 2-FF + 0.

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