1,845 research outputs found
Opsin vs opsin: new materials for biotechnological applications
The need of new diagnostic methods satisfying, as an early detection, a low
invasive procedure and a cost-efficient value, is orienting the technological
research toward the use of bio-integrated devices, in particular bio-sensors.
The set of know-why necessary to achieve this goal is wide, from biochemistry
to electronics and is summarized in an emerging branch of electronics, called
\textit{proteotronics}. Proteotronics is here here applied to state a
comparative analysis of the electrical responses coming from type-1 and type-2
opsins. In particular, the procedure is used as an early investigation of a
recently discovered family of opsins, the proteorhodopsins activated by blue
light, BPRs. The results reveal some interesting and unexpected similarities
between proteins of the two families, suggesting the global electrical response
are not strictly linked to the class identity.Comment: 10 pages, 8 figures revised version with more figure
Hierarchy and assortativity as new tools for affinity investigation: the case of the TBA aptamer-ligand complex
Aptamers are single stranded DNA, RNA or peptide sequences having the ability
to bind a variety of specific targets (proteins, molecules as well as ions).
Therefore, aptamer production and selection for therapeutic and diagnostic
applications is very challenging. Usually they are in vitro generated, but,
recently, computational approaches have been developed for the in silico
selection, with a higher affinity for the specific target. Anyway, the
mechanism of aptamer-ligand formation is not completely clear, and not obvious
to predict. This paper aims to develop a computational model able to describe
aptamer-ligand affinity performance by using the topological structure of the
corresponding graphs, assessed by means of numerical tools such as the
conventional degree distribution, but also the rank-degree distribution
(hierarchy) and the node assortativity. Calculations are applied to the
thrombin binding aptamer (TBA), and the TBA-thrombin complex, produced in the
presence of Na+ or K+. The topological analysis reveals different affinity
performances between the macromolecules in the presence of the two cations, as
expected by previous investigations in literature. These results nominate the
graph topological analysis as a novel theoretical tool for testing affinity.
Otherwise, starting from the graphs, an electrical network can be obtained by
using the specific electrical properties of amino acids and nucleobases.
Therefore, a further analysis concerns with the electrical response, which
reveals that the resistance sensitively depends on the presence of sodium or
potassium thus posing resistance as a crucial physical parameter for testing
affinity.Comment: 12 pages, 5 figure
Investigations on the electrical current-voltage response in protein light receptors
We report a theoretical/computational approach for modeling the
current-voltage characteristics of sensing proteins. The modeling is applied to
a couple of transmembrane proteins, bacteriorhodopsin and proteorhodopsin,
sensitive to visible light and promising biomaterials for the development of a
new generation of photo-transducers. The agreement between theory and
experiments sheds new light on the microscopic interpretation of charge
transfer in proteins and biological materials in general.Comment: 4 pages, 3 figures To be published in J Phys. C: Conf Ser. Proceeding
of the Conference IC-MCSQUARE, PRAGUE 201
The role of topology in electrical properties of bacteriorhodopsin and rat olfactory receptor I7
We report on electrical properties of the two sensing proteins:
bacteriorhodopsin and rat olfactory receptor OR-I7. As relevant transport
parameters we consider the small-signal impedance spectrum and the static
current-voltage characteristics. Calculations are compared with available
experimental results and the model predictability is tested for future
perspectives.Comment: 4 pages, 4 figure
Olfactory receptors for a smell sensor: A comparative study of the electrical responses of rat I7 and human 17-40
In this paper we explore relevant electrical properties of two olfactory
receptors (ORs), one from rat OR I7 and the other from human OR 17-40, which
are of interest for the realization of smell nanobiosensors. The investigation
compares existing experiments, coming from electrochemical impedance
spectroscopy, with the theoretical expectations obtained from an impedance
network protein analogue, recently developed. The changes in the response due
to the sensing action of the proteins are correlated with the conformational
change undergone by the single protein. The satisfactory agreement between
theory and experiments points to a promising development of a new class of
nanobiosensors based on the electrical properties of sensing proteins.Comment: 6 pages, 7 figure
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