Site-specific immobilization of CMP-sialic acid synthetase on magnetic nanoparticles and its use in the synthesis of CMP-sialic acid

2008 ◽  
pp. 1308 ◽  
Author(s):  
Ching-Ching Yu ◽  
Po-Chiao Lin ◽  
Chun-Cheng Lin
Keyword(s):  
Sialic Acid ◽  
Magnetic Nanoparticles ◽  
Site Specific

Site-specific, covalent immobilization of an engineered enterokinase onto magnetic nanoparticles through transglutaminase-catalyzed bioconjugation

2019 ◽  
Vol 177 ◽  
pp. 506-511 ◽  
Author(s):  
Jing-Hong Wang ◽  
Ming-Ze Tang ◽  
Xiao-Tian Yu ◽  
Chong-Mei Xu ◽  
Hong-Ming Yang ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Covalent Immobilization ◽  
Site Specific

Site-Specific Introduction of Sialic Acid into Insulin

2004 ◽  
Vol 116 (12) ◽  
pp. 1542-1546 ◽  
Author(s):  
Masaaki Sato ◽  
Reiko Sadamoto ◽  
Kenichi Niikura ◽  
Kenji Monde ◽  
Hirosato Kondo ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Site Specific

scholarly journals Cross-species comparison of site-specific evolutionary-rate variation in influenza haemagglutinin

2013 ◽  
Vol 368 (1614) ◽  
pp. 20120334 ◽  
Author(s):  
Austin G. Meyer ◽  
Eric T. Dawson ◽  
Claus O. Wilke
Keyword(s):  
Protein Structure ◽  
Sialic Acid ◽  
Avian Influenza ◽  
Evolutionary Rate ◽  
Solvent Accessibility ◽  
Rate Variation ◽  
Structural Constraints ◽  
Binding Region ◽  
Site Specific ◽  
Sialic Acid Binding

We investigate the causes of site-specific evolutionary-rate variation in influenza haemagglutinin (HA) between human and avian influenza, for subtypes H1, H3, and H5. By calculating the evolutionary-rate ratio, ω = d N /d S as a function of a residue's solvent accessibility in the three-dimensional protein structure, we show that solvent accessibility has a significant but relatively modest effect on site-specific rate variation. By comparing rates within HA subtypes among host species, we derive an upper limit to the amount of variation that can be explained by structural constraints of any kind. Protein structure explains only 20–40% of the variation in ω . Finally, by comparing ω at sites near the sialic-acid-binding region to ω at other sites, we show that ω near the sialic-acid-binding region is significantly elevated in both human and avian influenza, with the exception of avian H5. We conclude that protein structure, HA subtype, and host biology all impose distinct selection pressures on sites in influenza HA.

scholarly journals Quantifying intracellular trafficking of silica-coated magnetic nanoparticles in live single cells by site-specific direct stochastic optical reconstruction microscopy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Suresh Kumar Chakkarapani ◽  
Tae Hwan Shin ◽  
Seungah Lee ◽  
Kyung-Soo Park ◽  
Gwang Lee ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Intracellular Trafficking ◽  
Biomedical Applications ◽  
Single Cells ◽  
Raw 264.7 Cells ◽  
Raw 264.7 ◽  
Nih3t3 Cells ◽  
Site Specific ◽  
Stochastic Optical Reconstruction Microscopy ◽  
Optical Reconstruction

Abstract Background Nanoparticles have been used for biomedical applications, including drug delivery, diagnosis, and imaging based on their unique properties derived from small size and large surface-to-volume ratio. However, concerns regarding unexpected toxicity due to the localization of nanoparticles in the cells are growing. Herein, we quantified the number of cell-internalized nanoparticles and monitored their cellular localization, which are critical factors for biomedical applications of nanoparticles. Methods This study investigates the intracellular trafficking of silica-coated magnetic nanoparticles containing rhodamine B isothiocyanate dye [MNPs@SiO2(RITC)] in various live single cells, such as HEK293, NIH3T3, and RAW 264.7 cells, using site-specific direct stochastic optical reconstruction microscopy (dSTORM). The time-dependent subdiffraction-limit spatial resolution of the dSTORM method allowed intracellular site-specific quantification and tracking of MNPs@SiO2(RITC). Results The MNPs@SiO2(RITC) were observed to be highly internalized in RAW 264.7 cells, compared to the HEK293 and NIH3T3 cells undergoing single-particle analysis. In addition, MNPs@SiO2(RITC) were internalized within the nuclei of RAW 264.7 and HEK293 cells but were not detected in the nuclei of NIH3T3 cells. Moreover, because of the treatment of the MNPs@SiO2(RITC), more micronuclei were detected in RAW 264.7 cells than in other cells. Conclusion The sensitive and quantitative evaluations of MNPs@SiO2(RITC) at specific sites in three different cells using a combination of dSTORM, transcriptomics, and molecular biology were performed. These findings highlight the quantitative differences in the uptake efficiency of MNPs@SiO2(RITC) and ultra-sensitivity, varying according to the cell types as ascertained by subdiffraction-limit super-resolution microscopy. Graphical Abstract

A novel Fe3O4/CdTe fluorescence probe for sialic acid detection based on a phenylboronic acid–sialic acid recognition system

RSC Advances ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 481-488 ◽  
Author(s):  
Jinna Wang ◽  
Guanhong Xu ◽  
Fangdi Wei ◽  
Jing Yang ◽  
Ping Zhou ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Magnetic Nanoparticles ◽  
Fluorescence Probe ◽  
Phenylboronic Acid ◽  
Recognition System ◽  
Fluorescence Method ◽  
System P

A novel fluorescence method was established for detecting sialic acid (SA) by using phenylboronic acid (PBA)-functionalized Fe3O4/CdTe magnetic nanoparticles as fluorescence probe.

scholarly journals Post-Glycosylation Modification of Sialic Acid and Its Role in Virus Pathogenesis

Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 171 ◽  
Author(s):  
Park
Keyword(s):  
Sialic Acid ◽  
Mammalian Cells ◽  
Biological Significance ◽  
Extraction Methods ◽  
Sialic Acids ◽  
Neuraminic Acid ◽  
Host Cells ◽  
Viral Receptor ◽  
Site Specific ◽  
Viral Binding

Sialic acids are a family of nine carbon keto-aldononulosonic acids presented at the terminal ends of glycans on cellular membranes. α-Linked sialoglycoconjugates often undergo post-glycosylation modifications, among which O-acetylation of N-acetyl neuraminic acid (Neu5Ac) is the most common in mammalian cells. Isoforms of sialic acid are critical determinants of virus pathogenesis. To date, the focus of viral receptor-mediated attachment has been on Neu5Ac. O-Acetylated Neu5Acs have been largely ignored as receptor determinants of virus pathogenesis, although it is ubiquitous across species. Significantly, the array of structures resulting from site-specific O-acetylation by sialic acid O-acetyltransferases (SOATs) provides a means to examine specificity of viral binding to host cells. Specifically, C4 O-acetylated Neu5Ac can influence virus pathogenicity. However, the biological implications of only O-acetylated Neu5Ac at C7–9 have been explored extensively. This review will highlight the biological significance, extraction methods, and synthetic modifications of C4 O-acetylated Neu5Ac that may provide value in therapeutic developments and targets to prevent virus related diseases.

Site-Specific Immobilization of Enzymes on Magnetic Nanoparticles and Their Use in Organic Synthesis

2012 ◽  
Vol 23 (4) ◽  
pp. 714-724 ◽  
Author(s):  
Ching-Ching Yu ◽  
Yu-Ying Kuo ◽  
Chien-Fu Liang ◽  
Wei-Ting Chien ◽  
Huan-Ting Wu ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Organic Synthesis ◽  
Site Specific ◽  
Immobilization Of Enzymes

scholarly journals A Linkage-specific Sialic Acid Labeling Strategy Reveals Different Site-specific Glycosylation Patterns in SARS-CoV-2 Spike Protein Produced in CHO and HEK Cell Substrates

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiong Wang ◽  
Yan Wang ◽  
Shuang Yang ◽  
Changyi Lin ◽  
Lateef Aliyu ◽  
...  
Keyword(s):  
Immune System ◽  
Sialic Acid ◽  
Viral Envelope ◽  
Site Specific ◽  
S Protein ◽  
Hek Cells ◽  
High Mannose ◽  
The Impact ◽  
S Proteins ◽  
Spike Proteins

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus utilizes the extensively glycosylated spike (S) protein protruding from the viral envelope to bind to angiotensin-converting enzyme-related carboxypeptidase (ACE2) as its primary receptor to mediate host-cell entry. Currently, the main recombinant S protein production hosts are Chinese hamster ovary (CHO) and human embryonic kidney (HEK) cells. In this study, a recombinant S protein truncated at the transmembrane domain and engineered to express a C-terminal trimerization motif was transiently produced in CHO and HEK cell suspensions. To further evaluate the sialic acid linkages presenting on S protein, a two-step amidation process, employing dimethylamine and ammonium hydroxide reactions in a solid support system, was developed to differentially modify the sialic acid linkages on the glycans and glycopeptides from the S protein. The process also adds a charge to Asp and Glu which aids in ionization. We used MALDI-TOF and LC-MS/MS with electron-transfer/higher-energy collision dissociation (EThcD) fragmentation to determine global and site-specific N-linked glycosylation patterns. We identified 21 and 19 out of the 22 predicted N-glycosites of the SARS-CoV-2 S proteins produced in CHO and HEK, respectively. It was found that the N-glycosite at 1,158 position (N1158) and at 122, 282 and 1,158 positions (N122, N282 and N1158) were absent on S from CHO and HEK cells, respectively. The structural mapping of glycans of recombinant human S proteins reveals that CHO-Spike exhibits more complex and higher sialylation (α2,3-linked) content while HEK-Spike exhibits more high-mannose and a small amount of α2,3- and α2,6-linked sialic acids. The N74 site represents the most abundant glycosite on both spike proteins. The relatively higher amount of high-mannose abundant sites (N17, N234, N343, N616, N709, N717, N801, and N1134) on HEK-Spike suggests that glycan-shielding may differ among the two constructs. HEK-Spike can also provide different host immune system interaction profiles based on known immune system active lectins. Collectively, these data underscore the importance of characterizing the site-specific glycosylation of recombinant human spike proteins from HEK and CHO cells in order to better understand the impact of the production host on this complex and important protein used in research, diagnostics and vaccines.

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