11 research outputs found
A clinical diagnostic model for predicting influenza among young adult military personnel with febrile respiratory illness in Singapore
10.1371/journal.pone.0017468PLoS ONE63
Protein/Peptide Aggregation and Amyloidosis on Biointerfaces
Recently, studies of protein/peptide aggregation, particularly the amyloidosis, have attracted considerable attention in discussions of the pathological mechanisms of most neurodegenerative diseases. The protein/peptide aggregation processes often occur at the membrane–cytochylema interface in vivo and behave differently from those occurring in bulk solution, which raises great interest to investigate how the interfacial properties of artificial biomaterials impact on protein aggregation. From the perspective of bionics, current progress in this field has been obtained mainly from four aspects: (1) hydrophobic–hydrophilic interfaces; (2) charged surface; (3) chiral surface; and (4) biomolecule-related interfaces. The specific physical and chemical environment provided by these interfaces is reported to strongly affect the adsorption of proteins, transition of protein conformation, and diffusion of proteins on the biointerface, all of which are ultimately related to protein assembly. Meanwhile, these compelling results of in vitro experiments can greatly promote the development of early diagnostics and therapeutics for the relevant neurodegenerative diseases. This paper presents a brief review of these appealing studies, and particular interests are placed on weak interactions (i.e., hydrogen bonding and stereoselective interactions) that are also non-negligible in driving amyloid aggregation at the interfaces. Moreover, this paper also proposes the future perspectives, including the great opportunities and challenges in this field as well
Developing an Inositol-Phosphate-Actuated Nanochannel System by Mimicking Biological Calcium Ion Channels
In
eukaryotic cells, ion channels, which ubiquitously present as polypeptides
or proteins, usually regulate the ion transport across biological
membranes by conformational switching of the channel proteins in response
to the binding of diverse signaling molecules (e.g., inositol phosphate,
abbreviated to InsP). To mimic the gating behaviors of natural Ca<sup>2+</sup> channels manipulated by InsPs, a smart poly[(<i>N</i>-isopropylacrylamide-<i>co</i>-4-(3-acryloylthioureido)
benzoic acid)<sub>0.2</sub>] (denoted as PNI-<i>co</i>-ATBA<sub>0.2</sub>) was integrated onto a porous anodic alumina (PAA) membrane,
building an InsP-actuated nanochannel system. Driven by the intensive
hydrogen bonding complexation of ATBA monomer with InsP, the copolymer
chains displayed a remarkable and reversible conformational transition
from a contracted state to a swollen one, accompanied with significant
changes in surface morphology, wettability, and viscoelasticity. Benefiting
from these features, dynamic gating behaviors of the nanochannels
located on the copolymer-modified PAA membrane could be precisely
manipulated by InsPs, reflected as a satisfactory linear relationship
between real-time variation in transmembrane ionic current and the
InsP concentration over a wide range from 1 nmol L<sup>–1</sup> to 10 μmol L<sup>–1</sup>, as well as a clear discrimination
among InsP<sub>2</sub>, InsP<sub>3</sub>, and InsP<sub>6</sub>. This
study indicates the great potential of biomolecule-responsive polymers
in the fabrication of biomimetic ion nanochannels and other nanoscale
biodevices