scholarly journals Rapid Glycoconjugation with Glycosyl Amines

2021 ◽  
Author(s):  
Mareike A. Rapp ◽  
Oliver R. Baudendistel ◽  
Ulrich E. Steiner ◽  
Valentin Wittmann
Keyword(s):  
Biological Functions ◽  
Chemoselective Ligation

Conjugation of unprotected carbohydrates to surfaces or probes by chemoselective ligation reactions is indispensable for the elucidation of their numerous biological functions. Especially the reaction with oxyamines leading to the...

Membrane–cytoskeleton interactions in cholesterol-dependent domain formation

2015 ◽  
Vol 57 ◽  
pp. 177-187 ◽  
Author(s):  
Jennifer N. Byrum ◽  
William Rodgers
Keyword(s):  
Biological Properties ◽  
Membrane Rafts ◽  
Membrane Domains ◽  
Biological Functions ◽  
Membrane Cytoskeleton ◽  
Heterogeneous Structures ◽  
Integral Role ◽  
Model Cell ◽  
Actomyosin Cytoskeleton ◽  
Dependent Domain

Since the inception of the fluid mosaic model, cell membranes have come to be recognized as heterogeneous structures composed of discrete protein and lipid domains of various dimensions and biological functions. The structural and biological properties of membrane domains are represented by CDM (cholesterol-dependent membrane) domains, frequently referred to as membrane ‘rafts’. Biological functions attributed to CDMs include signal transduction. In T-cells, CDMs function in the regulation of the Src family kinase Lck (p56lck) by sequestering Lck from its activator CD45. Despite evidence of discrete CDM domains with specific functions, the mechanism by which they form and are maintained within a fluid and dynamic lipid bilayer is not completely understood. In the present chapter, we discuss recent advances showing that the actomyosin cytoskeleton has an integral role in the formation of CDM domains. Using Lck as a model, we also discuss recent findings regarding cytoskeleton-dependent CDM domain functions in protein regulation.

The Interaction of β2 Glycoprotein-I and Heparin and Its Effect on β2 Glycoprotein-I Antiphospholipid Antibody Cofactor Function in Plasma

1994 ◽  
Vol 72 (04) ◽  
pp. 578-581 ◽  
Author(s):  
T McNally ◽  
S E Cotterell ◽  
I J Mackie ◽  
D A Isenberg ◽  
S J Machin
Keyword(s):  
Solid Phase ◽  
Pharmaceutical Preparations ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antiphospholipid Antibody ◽  
Biological Functions ◽  
Dermatan Sulphate ◽  
Glycoprotein I ◽  
Crossed Immunoelectrophoresis ◽  
Calcium Heparin ◽  
Cofactor Activity

Summaryβ2 glycoprotein-I (β2GPI), a cofactor for antiphospholipid antibody (aPA) binding, binds to many anionic macromolecules including heparin. The nature of this interaction with heparin is not well understood and its effect on the purported biological functions of β2GPI is unknown.We have examined the interactions of dermatan sulphate (DS) and different pharmaceutical preparations of heparin with β2GPI by crossed immunoelectrophoresis (CIE) and investigated the effect of these agents on plasma levels of p2GPI antigen (β2GPI: Ag) by a standardised enzyme linked immunosorbent assay (ELISA). P2GPI aPA cofactor activity (β2GPI:Cof) was also measured using a modified solid phase an-ti-phosphatidylserine (aPS) ELISA. CIE results confirmed a heparin-β2GPI interaction with unfractionated (UF) heparin. β2GPI:Ag levels were unaffected by any of the preparations investigated. There were no significant differences in β2GPI:Cof activities of the samples containing LMW heparins or DS but levels of β2GPI:Cof were increased in samples containing UF sodium and calcium heparin preparations (0.5 IU/ml Monoparin, p <0.05, and 10 IU/ml Liquemin and Calcipa-rine, p <0.05).

Single-Molecule Imaging of Active Mitochondrial Nitroreductases using a Photo-Crosslinking Fluorescent Sensor

2019 ◽  
Author(s):  
Zacharias Thiel ◽  
Pablo Rivera-Fuentes
Keyword(s):  
Subcellular Localization ◽  
Fluorescent Probe ◽  
Single Molecule ◽  
Mammalian Cells ◽  
Fluorescent Sensor ◽  
Biological Functions ◽  
Localization Microscopy ◽  
Drug Activation ◽  
Nitroreductase Activity ◽  
Single Molecule Localization Microscopy

Many biomacromolecules are known to cluster in microdomains with specific subcellular localization. In the case of enzymes, this clustering greatly defines their biological functions. Nitroreductases are enzymes capable of reducing nitro groups to amines and play a role in detoxification and pro-drug activation. Although nitroreductase activity has been detected in mammalian cells, the subcellular localization of this activity remains incompletely characterized. Here, we report a fluorescent probe that enables super-resolved imaging of pools of nitroreductase activity within mitochondria. This probe is activated sequentially by nitroreductases and light to give a photo-crosslinked adduct of active enzymes. In combination with a general photoactivatable marker of mitochondria, we performed two-color, threedimensional, single-molecule localization microscopy. These experiments allowed us to image the sub-mitochondrial organization of microdomains of nitroreductase activity.<br>

Single-Molecule Imaging of Active Mitochondrial Nitroreductases using a Photo-Crosslinking Fluorescent Sensor

2019 ◽  
Author(s):  
Zacharias Thiel ◽  
Pablo Rivera-Fuentes
Keyword(s):  
Subcellular Localization ◽  
Fluorescent Probe ◽  
Single Molecule ◽  
Mammalian Cells ◽  
Fluorescent Sensor ◽  
Biological Functions ◽  
Localization Microscopy ◽  
Drug Activation ◽  
Nitroreductase Activity ◽  
Single Molecule Localization Microscopy

Many biomacromolecules are known to cluster in microdomains with specific subcellular localization. In the case of enzymes, this clustering greatly defines their biological functions. Nitroreductases are enzymes capable of reducing nitro groups to amines and play a role in detoxification and pro-drug activation. Although nitroreductase activity has been detected in mammalian cells, the subcellular localization of this activity remains incompletely characterized. Here, we report a fluorescent probe that enables super-resolved imaging of pools of nitroreductase activity within mitochondria. This probe is activated sequentially by nitroreductases and light to give a photo-crosslinked adduct of active enzymes. In combination with a general photoactivatable marker of mitochondria, we performed two-color, threedimensional, single-molecule localization microscopy. These experiments allowed us to image the sub-mitochondrial organization of microdomains of nitroreductase activity.<br>

Biological functions of HD-Zip transcription factors

2013 ◽  
Vol 35 (10) ◽  
pp. 1179-1188 ◽  
Author(s):  
Hong WANG ◽  
Gang-Bo LI ◽  
Da-Yong ZHANG ◽  
Jing LIN ◽  
Bao-Long SHENG ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Biological Functions

Mechanism of the Protective Effect of Sesamin on Sepsis-Induced Acute Lung Injury

2020 ◽  
Vol 19 (2) ◽  
pp. 211-216
Author(s):  
Hui Chen ◽  
Longhuan Zeng ◽  
Guangwei Jiang ◽  
Qian Liu
Keyword(s):  
Theoretical Basis ◽  
Pulmonary Inflammation ◽  
Cecal Ligation ◽  
Case Fatality ◽  
Oxidative Stress Response ◽  
Inflammatory Factors ◽  
Common Denominator ◽  
Biological Functions ◽  
Sepsis Model ◽  
Rational Plan

Sepsis is the syndrome of systemic inflammatory response caused by infection. Over 20 million people worldwide suffer from sepsis each year, of whom about 6 million die, with a case-fatality rate of more than 25%. Therefore, to develop a rational plan for the management of sepsis, there is an urgent need to understand the mechanism of pathogenesis. Sesamin is a kind of sesame lignin isolated from sesame that exhibits multiple biological functions including antiviral, antidyslipidemic, and antihypertensive to name a few. An antioxidant and anti-inflammatory activity of sesamin appears to be a common denominator in all of its biologic activities. However, the mechanism of sesamin on septic-induced acute pulmonary inflammation still needs further study. Herein, we have established a sepsis model of C57BL/6 mice by cecal ligation and perforation. Using this model, we have shown that sesamin could reduce the levels of several inflammatory factors as well as oxidative stress response. Furthermore, sesamin could repress NLRP3 inflammasome and activate Nrf2/HO-1 pathway, and further inhibit acute pulmonary inflammation. This study reveals the mechanism of the diminution of septic-induced acute pulmonary inflammation by sesamin. This opens a theoretical basis for the development of drugs for treatment of sepsis.

From Ocean to Bedside: the Therapeutic Potential of Molluscan Hemocyanins

2018 ◽  
Vol 25 (20) ◽  
pp. 2292-2303 ◽  
Author(s):  
Negar Talaei Zanjani ◽  
Monica Miranda Saksena ◽  
Fariba Dehghani ◽  
Anthony L. Cunningham
Keyword(s):  
Antiviral Activity ◽  
Clinical Efficacy ◽  
Mechanism Of Action ◽  
Therapeutic Agent ◽  
Marine Invertebrates ◽  
Therapeutic Potential ◽  
Biological Functions ◽  
Anticancer Properties ◽  
Mechanistic Understanding

Hemocyanins are large and versatile glycoproteins performing various immunological and biological functions in many marine invertebrates including arthropods and molluscs. This review discusses the various pharmacological applications of mollusc hemocyanin such as antiviral activity, immunostimulatory and anticancer properties that have been reported in the literature between the years 2000 and 2016. Emphasis is placed on a better mechanistic understanding of hemocyanin as a therapeutic agent. Elucidation of the mechanism of action is essential to improve the clinical efficacy and for a better understanding of some endogenous immunological functions of this complex glycoprotein.

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