scholarly journals Indirect Microcontact Printing to Create Functional Patterns of Physisorbed Antibodies

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3163 ◽  
Author(s):  
Augusto Juste-Dolz ◽  
Miquel Avella-Oliver ◽  
Rosa Puchades ◽  
Angel Maquieira
Keyword(s):  
Biological Activity ◽  
Bovine Serum Albumin ◽  
Conformational Changes ◽  
Immunoglobulin E ◽  
Microcontact Printing ◽  
Label Free ◽  
Simple Strategy ◽  
Solid Substrates ◽  
Functional Patterns ◽  
Nanostructured Patterns

Microcontact printing (µCP) is a practical and versatile approach to create nanostructured patterns of biomolecular probes, but it involves conformational changes on the patterned bioreceptors that often lead to a loss on the biological activity of the resulting structures. Herein we introduce indirect µCP to create functional patterns of bioreceptors on solid substrates. This is a simple strategy that relies on physisorbing biomolecular probes of interest in the nanostructured gaps that result after patterning backfilling agents by standard µCP. This study presents the approach, assesses bovine serum albumin as backfilling agent for indirect µCP on different materials, reports the limitations of standard µCP on the functionality of patterned antibodies, and demonstrates the capabilities of indirect µCP to solve this issue. Bioreceptors were herein structured as diffractive gratings and used to measure biorecognition events in label-free conditions. Besides, as a preliminary approach towards sensing biomarkers, this work also reports the implementation of indirect µCP in an immunoassay to detect human immunoglobulin E.

scholarly journals Structural control of fibrin bioactivity by mechanical deformation

2020 ◽  
Author(s):  
Sachin Kumar ◽  
Yujen Wang ◽  
Manuel K. Rausch ◽  
Sapun H. Parekh
Keyword(s):  
Biological Activity ◽  
Conformational Changes ◽  
Structural Control ◽  
Structural Changes ◽  
Tensile Deformation ◽  
Mechanical Strain ◽  
Fibrous Protein ◽  
Binding Partners ◽  
Blood Clots ◽  
Β Sheet

AbstractFibrin is a fibrous protein network that entraps blood cells and platelets to form blood clots following vascular injury. As a biomaterial, fibrin acts a biochemical scaffold as well as a viscoelastic patch that resists mechanical insults. The biomechanics and biochemistry of fibrin have been well characterized independently, showing that fibrin is a hierarchical material with numerous binding partners. However, comparatively little is known about how fibrin biomechanics and biochemistry are coupled: how does fibrin deformation influence its biochemistry at the molecular level? In this study, we show how mechanically-induced molecular structural changes in fibrin affect fibrin biochemistry and fibrin-platelet interaction. We found that tensile deformation of fibrin lead to molecular structural transitions of α-helices to β-sheets, which reduced binding of tissue plasminogen activator (tPA), an enzyme that initiates fibrinolysis, at the network and single fiber level. Moreover, binding of tPA and Thioflavin T (ThT), a commonly used β-sheet marker, was primarily mutually exclusive such that tPA bound to native (helical) fibrin whereas ThT bound to strained fibrin. Finally, we demonstrate that conformational changes in fibrin suppressed the biological activity of platelets on mechanically strained fibrin due to attenuated αIIbβ3 integrin binding. Our work shows that mechanical strain regulates fibrin molecular structure and fibrin biological activity in an elegant mechano-chemical feedback loop, which likely influences fibrinolysis and wound healing kinetics.

scholarly journals Harnessing intrinsic fluorescence for typing of secondary structures of DNA

2020 ◽  
Author(s):  
Michela Zuffo ◽  
Aurélie Gandolfini ◽  
Brahim Heddi ◽  
Anton Granzhan
Keyword(s):  
High Throughput ◽  
Conformational Changes ◽  
Emission Spectra ◽  
Principal Component ◽  
Secondary Structures ◽  
Intrinsic Fluorescence ◽  
Label Free ◽  
Linear Discriminant ◽  
Effective Manner

ABSTRACTDNA is polymorphic since, despite its ubiquitous presence as a double-stranded helix, it is able to fold into a plethora of other secondary structures both in vitro and in cells. Despite the considerable advances that have been made in understanding this structural diversity, its high-throughput investigation still faces severe limitations. This mainly stems from the lack of suitable label-free methods, combining a fast and cheap experimental workflow with high information content. Here, we explore the use of intrinsic fluorescence emitted by nucleic acids for this scope. After a preliminary assessment of the suitability of this phenomenon for tracking the conformational changes of DNA, we examined the intrinsic steady-state emission spectra of an 89-membered set of synthetic oligonucleotides with reported conformation (G-quadruplexes, i-motifs, single- and double stranded DNA) by means of multivariate analysis. Specifically, principal component analysis of emission spectra resulted in successful clustering of oligonucleotides into three corresponding conformational groups, albeit without discrimination between single- and double-stranded structures. Linear discriminant analysis of the same training set was exploited for the assessment of new sequences, allowing the evaluation of their G4-forming propensity. Our method does not require any labelling agent or dye, avoiding the related intrinsic bias, and can be utilized to screen novel sequences of interest in a high-throughput and cost-effective manner. In addition, we observed that left-handed (Z-) G4 structures were systematically more fluorescent than most other G4 structures, almost reaching the quantum yield of 5′-d[(G3T)3G3]-3′ (G3T), the most fluorescent G4 structure reported to date. This property is likely to arise from the similar base-stacking geometry in both types of structures.

scholarly journals A Fluorescent Biosensor Reveals Conformational Changes in Human Immunoglobulin E Fc

2012 ◽  
Vol 287 (21) ◽  
pp. 17459-17470 ◽  
Author(s):  
James Hunt ◽  
Anthony H. Keeble ◽  
Robert E. Dale ◽  
Melissa K. Corbett ◽  
Rebecca L. Beavil ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Immunoglobulin E ◽  
Human Immunoglobulin ◽  
Fluorescent Biosensor

scholarly journals Ligand-Induced Conformational Changes in HSP90 Monitored Time Resolved and Label Free-Towards a Conformational Activity Screening for Drug Discovery

2018 ◽  
Vol 57 (31) ◽  
pp. 9955-9960 ◽  
Author(s):  
Jörn Güldenhaupt ◽  
Marta Amaral ◽  
Carsten Kötting ◽  
Jonas Schartner ◽  
Djordje Musil ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Conformational Changes ◽  
Label Free ◽  
Time Resolved ◽  
Activity Screening

scholarly journals Insight to Functional Conformation and Noncovalent Interactions of Protein-Protein Assembly Using MALDI Mass Spectrometry

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4979
Author(s):  
Marco Giampà ◽  
Elvira Sgobba
Keyword(s):  
Mass Spectrometry ◽  
Conformational Changes ◽  
Protein Interactions ◽  
Noncovalent Interactions ◽  
Conformational Dynamics ◽  
High Sensitivity ◽  
Maldi Mass Spectrometry ◽  
Noncovalent Interaction ◽  
Ionization Mass ◽  
Label Free

Noncovalent interactions are the keys to the structural organization of biomolecule e.g., proteins, glycans, lipids in the process of molecular recognition processes e.g., enzyme-substrate, antigen-antibody. Protein interactions lead to conformational changes, which dictate the functionality of that protein-protein complex. Besides biophysics techniques, noncovalent interaction and conformational dynamics, can be studied via mass spectrometry (MS), which represents a powerful tool, due to its low sample consumption, high sensitivity, and label-free sample. In this review, the focus will be placed on Matrix-Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS) and its role in the analysis of protein-protein noncovalent assemblies exploring the relationship within noncovalent interaction, conformation, and biological function.

Sign in / Sign up

Export Citation Format

Share Document