• Journal of Ginseng Research
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• 제13권2호
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• pp.215-222
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• 1989

A macromolecular fraction from fresh ginseng root containing mainly polysaccharide showed mild mitogenic activity in human cord blood lymphocytes. 2) When lymphocytes were transformed by Con A or PHA, this fraction could greatly enhance the activity of these lectin mitogens, thus showing a potentiation effect. 3) Although this macromolerular fraction contains saponin and is susceptible to trypsin digestion, it is probably a peptido-glycan in nature on account of its important carbohydrate content and thermal stability. 4) This fraction could not support cancer cell (EAT, K562) growth : its inhibitory effect on these cells remains to be explored.

• BMB Reports
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• 제45권6호
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• pp.323-330
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• 2012

The glycome consists of all glycans (or carbohydrates) within a biological system, and modulates a wide range of important biological activities, from protein folding to cellular communications. The mining of the glycome for disease markers represents a new paradigm for biomarker discovery; however, this effort is severely complicated by the vast complexity and structural diversity of glycans. This review summarizes recent developments in analytical technology and methodology as applied to the fields of glycomics and glycoproteomics. Mass spectrometric strategies for glycan compositional profiling are described, as are potential refinements which allow structure-specific profiling. Analytical methods that can discern protein glycosylation at a specific site of modification are also discussed in detail. Biomarker discovery applications are shown at each level of analysis, highlighting the key role that glycoscience can play in helping scientists understand disease biology.

• Mass Spectrometry Letters
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• 제6권3호
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• pp.53-58
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• 2015

Recombinant erythropoietins (EPOs) are an important class of biotherapeutics that stimulate red blood cell production. The quality, safety, and potency of EPO variants are determined largely by their glycosylation, which makes up nearly half their mass. Thus, detailed glycomic analyses are important to assess biotherapeutic quality and establish the equivalency of biosimilar EPOs now coming to market. High-resolution mass spectrometry (MS) has recently emerged as the premier tool for glycan analysis in EPOs. Using the accurate mass measurements provided by high-resolution MS, the compositions of even large, complex glycans can easily be determined. When combined with a nano-LC separation, differentiation of structural isomers also becomes a possibility. These components, together, provide a comprehensive picture of biotherapeutic glycosylation. In this review, we provide an overview of MS-based analytical platform for glycomic characterization of EPO biotherapeutics and biosimilars.

• 미생물학회지
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• 제24권3호
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• pp.228-235
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• 1986

Zymomonas mobilis의 spheroplast 형성과 새생조건의 새량과 초|소배시에서의 새생에 대해서 연구하였다. Tris-maleate buffer (pH 5~6), $Ca^{++}$ ions 그러고 EDTA등은 out야 membrane의 투과성 변화를 야기시 켰다 Zymommonas의 세포벽은 lysozyme, mutanolysin같은 세포벽 분해효소에 의해 분해가 되지 않은 것처럼 보였고 sphe-roplast 생성에 glycine 처리는 필수적이었다. 그러나 lysozyme 처리에 의해서 spheroplast 형성이 촉진되는 것을 확인하였다. 따라서 ly sozyme과 glycine을 함께 처리함으로서 spheroplasting배지에서의 처리시간을 4시간으로 단축 할 수 있었고 재생율이 7-10% 증가되었다.

• Genomics & Informatics
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• 제8권2호
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• pp.63-69
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• 2010

Monofunctional biosynthetic peptidoglycan transglycosylase (MBPT) catalyzes the formation of the glycan chain in bacterial cell walls from peptidoglycan subunits: N-acetylglucosamine (NAG) and acetylmuramic acid (NAM). Bifunctional glycosyltransferases such as the penicillin binding protein (PBP) have peptidoglycan glycosyltransferase (PGT) on their C terminal end which links together the peptidoglycan subunits while transpeptidase (TP) on the N terminal end cross-links the peptide moieties on the NAM monosaccharide of the peptide subunits to create the bacterial cell wall. The singular function of MBPT resembles the C terminal end of PBP as it too contains and utilizes a similar PGT domain. In this article we analyzed the infectious and non infectious protein sequences of MBPT from 31 different strains of bacteria using a variety of bioinformatic tools. Motif analysis, dot-plot comparison, and phylogenetic analysis identified a number of significant differences between infectious and non-infectious protein sequences. In this paper we have made an attempt to explain, analyze and discuss these differences from an evolutionary perspective. The results of our sequence analysis may open the door for utilizing MBPT as a new target to fight a variety of infectious bacteria.

• Mass Spectrometry Letters
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• 제13권4호
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• pp.139-145
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• 2022

Protein glycosylation is a common post-translational modification by non-template-based biosynthesis. In fungal biotechnology, which has great applications in pharmaceuticals and industries, the importance of research on fungal glycoproteins and glycans is accelerating. In particular, the importance of quantitative analysis of fungal glycans is emerging in research on the production of filamentous fungal proteins by genetic modification. Reliable mass spectrometry-based techniques for quantitative glycomics have evolved into chemical, enzymatic, and metabolic stable isotope labeling methods. In this study, we intend to expand quantitative glycomics by metabolic isotope labeling of glycans in Aspergillus niger, a filamentous fungus model, by the MILPIG method. We demonstrate that incubation of filamentous fungi in a culture medium with carbon-13 labeled glucose (1-¹³C₁) efficiently incorporates carbon-13 into N-linked glycans. In addition, for quantitative validation of this method, light and heavy glycans are mixed 1:1 to show the performance of quantitative analysis of various N-linked glycans simultaneously. We have successfully quantified fungal glycans by MILPIG and expect it to be widely applicable to glycan expression levels under various biological conditions in fungi.

• Biomolecules & Therapeutics
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• 제31권2호
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• pp.141-147
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• 2023

Antibiotic resistance has emerged as a global threat to modern healthcare systems and has nullified many commonly used antibiotics. β-Lactam antibiotics are among the most successful and occupy approximately two-thirds of the prescription antibiotic market. They inhibit the synthesis of the peptidoglycan layer in the bacterial cell wall by mimicking the D-Ala-D-Ala in the pentapeptide crosslinking neighboring glycan chains. To date, various β-lactam antibiotics have been developed to increase the spectrum of activity and evade drug resistance. This review emphasizes the three-dimensional structural characteristics of β-lactam antibiotics regarding the overall scaffold, working mechanism, chemical diversity, and hydrolysis mechanism by β-lactamases. The structural insight into various β-lactams will provide an in-depth understanding of the antibacterial efficacy and susceptibility to drug resistance in multidrug-resistant bacteria and help to develop better β-lactam antibiotics and inhibitors.

• Journal of Life Science
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• 제10권1호
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• pp.51-56
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• 2000

In many cases of human cancer, the appearance of hypersialylated glycan structures is related to a precise stage of the disease ; this may depend on the elebated sialyltransferase activity during carcinogenesis. The aim of this study was to investigate the inhibitory effects of Oriental medicinal herbs on enzymatic activities of two kinds ofsialyltransferase, Gal $\beta$ 1,3GalNAc$\alpha$2,3-sialyltransferase(ST3Gal I) and Gal $\beta$ 1,4GlcNAc $\alpha$2,6-sialyltransterases(ST6Gal I), which are well known as glycosyltransterases associated with cancer. The aqueous extracts of Scutellaria Baicalensis Georgi, Coptidis Rhizoma, Glycyrrhiza urlensis Fisch, Bupleuri Radix and Platycodi Radix were prepared and tested, respectively. At concentration of 100$\mu$g, Glycyrrhiza uralensis Fisch showed the highest inhibitory effects(about 42% and 57%, respectively) on ST3Gal Iand ST6Gal Iactivities. ST3GAl I was inhibited about 23% by Scutellaria baicalensi G댁햐, but not by the other samples, whereas ST6Gal I was inhibited about 20% and 40%,respectively, by Scutellaria baicalensis Georgi and Bupleuri Radix. All inhibitory effects were obtained in a concentration-dependent manner.

• Molecules and Cells
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• 제24권3호
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• pp.416-423
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• 2007

Alterations in the glycan chains of cell surface glycoconjugates are frequently involved biological processes such as cell-cell interaction, cell migration, differentiation and development. Cultured embryonic (E18) rat cortical neurons underwent apoptosis in response to camptothecin, and lectin histochemistry showed that binding to apoptotic neurons of FITC-conjugated Maackia amurensis agglutinin (MAA), which is specific for terminal ${\alpha}2,3$-sialic acid residues, increased progressively with increasing concentrations of camptothecin. Analysis of the total proteins of apoptotic neurons by SDS-PAGE, and lectin blotting using HRP-labeled MAA, revealed that the expression of terminal ${\alpha}2,3$-sialic acid residues on an unknown protein with an apparent molecular mass of 25.6 kDa also increased in apoptotic neurons. NP-HPLC analysis of the total cellular N-glycans of normal and apoptotic neurons demonstrated that the expression of structurally simpler biantennary types of N-glycans fell by 49% during apoptosis whereas the more branched triantennary types of N-glycans with terminal sialic acid residues increased by up to 59%. These results suggest that increased surface expression of ${\alpha}2,3$-sialic acid residues and hyperglycosylation of N-glycans is a common feature of cellular responses to changes in cell physiology such as tumorigenesis and apoptosis.

• 미생물학회지
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• 제46권1호
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• pp.96-103
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• 2010

단백질의 N-글리코실화는 대표적인 번역 후 변형 중의 하나로 진핵생물 뿐 아니라 원핵생물에서도 발견된다. N-글리코실화는 단백질 상의 N-글리코실 서열인 N-x-S/T 위치에 지질과 연결된 올리고당(lipid-linked oligosaccharide, LLO)으로부터 올리고당 전이효소(oligosaccharyltransferase, OTase) 활성에 의해 글리칸(glycan)이 전달되어 당단백질의 합성이 이루어진다. 본 연구에서는 OTase의 세포내 활성을 측정하기 위하여 5/6-carboxyltetramethylrhodamine (TAMRA)이 도입된 형광펩타이드 TAMRA-DA$\underline{N}$Y$\underline{T}$K-$NH_2$를 이용하였다. OTase활성 측정은 단일 서브유닛으로 효소의 활성을 갖는 운동핵 편모충류인 Leishmania major Stt3p와 병원성 미생물인 Campylobacter jejuni PglB를 진핵생물과 원핵생물의 모델 효소로 각각 사용하여 Saccharomyces cerevisiae와 C. jejuni 유래 LLO와 형광 펩타이드를 반응시켜 당-펩타이드를 합성하였다. 합성된 당-펩타이드를 미반응한 형광펩타이드와 분리 및 당-펩타이드의 정량 분석을 위하여 Tricine SDS-PAGE, ConA 렉틴 컬럼 및 fluorospectrophotometer, HPLC를 사용하였으며, 당-펩타이드 분석을 통해 각 방법의 장단점을 비교하였다. 비교 분석 결과 Tricine SDS-PAGE를 이용한 형광 이미지 분석과, 렉틴 컬럼을 통해 분리된 당-펩타이드의 fluorospectrophotometer 정량법에 비해, HPLC를 이용한 방법이 OTase에 의해 생성된 당-펩타이드를 분석하는데 더 정확하고 정량적인 값을 제시하는 것으로 확인되었다.