Amino-Acid-Encoded Supramolecular Self-Assembly Architectures: Near-Infrared Fluorescence–Photothermal Temperature Dual-Signal Sensing of Hydrogen Peroxide

Detection of hydrogen peroxide (H2O2) is important for maintaining human health and environmental safety because an abnormal intake of H2O2 can lead to serious pathological conditions. However, reported fluorescent probes are still limited to the visible region, and complementarity with other detection modes to further ensure reliable detection results and readable signal output has not been attempted. Herein, we modulated the self-assembly process of linear tripeptides and nonpeptide biomolecules by means of amino acid encoding, including supramolecular morphology and energy conversion pathways, to obtain self-assembled peptide architectures that combine high fluorescence brightness and comparable photothermal properties. Using this peptide self-assembler as a signal carrier, near-infrared fluorescence–photothermal temperature dual-signal detection of H2O2 was achieved for the first time with the assistance of gold nanoparticles, with limits of 0.16 μM for near-infrared (NIR) fluorescence detection and 12.0 μM for photothermal detection. Furthermore, the electrostatic spinning technique was used to deposit the conjugate onto cellulose acetate membranes, which facilitated portable fluorescence imaging sensing of H2O2 in real samples. This work not only develops the first NIR fluorescent–photothermal temperature sensor targeting H2O2 but also demonstrates an organizational approach using biocompatible peptides as building blocks, pushing nanotechnologies toward a greener and sustainable development path

Characterization, Polymorphism and Selection of Major Histocompatibility Complex (MHC) DAB Genes in Vulnerable Chinese Egret (<i>Egretta eulophotes</i>)

<div><p>The major histocompatibility complex (MHC) is an excellent molecular marker for the studies of evolutionary ecology and conservation genetics because it is a family of highly polymorphic genes that play a key role in vertebrate immune response. In this study, the functional genes of MHC Class II B (DAB) were isolated for the first time in a vulnerable species, the Chinese egret (<i>Egretta</i><i>eulophotes</i>). Using a full length DNA and cDNA produced by PCR and RACE methods, four potential MHC DAB loci were characterized in the genome of this egret and all four were expressed in liver and blood. At least four copies of the MHC gene complex were similar to two copies of the minimal essential MHC complex of chicken, but are less complex than the multiple copies expressed in passerine species. In MHC polymorphism, 19 alleles of exon 2 were isolated from 48 individuals using PCR. No stop codons or frameshift mutations were found in any of the coding regions. The signatures of positive selection detected in potential peptide-binding regions by Bayesian analysis, suggesting that all of these genes were functional. These data will provide the fundamental basis for further studies to elucidate the mechanisms and significance of MHC molecular adaptation in vulnerable Chinese egret and other ardeids.</p> </div

Additional file 1 of Integrated analysis of single-cell and bulk RNA sequencing data reveals prognostic characteristics of lysosome-dependent cell death-related genes in osteosarcoma

Supplementary Material

Amino acid alignment of transcribed Chinese egret MHC class II β chain sequences compared with those of other bird species.

<p><i>Dots</i> indicate identity with the Egeu-DAB1*01 sequence, <i>dashes</i> indicate gaps. Conserved residues characteristic of classical class II β chain molecules [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074185#B41" target="_blank">41</a>] are <i>shaded</i>. Amino acids that contact the peptide-binding region in the human DRβ molecule [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074185#B42" target="_blank">42</a>] are indicated with a <i>plus sign</i> (on alignment top). Cysteine bridges in the β1 and β2 domains are indicated by <i>brackets</i>. Residues in the β2 domain that are implicated in CD4 binding in humans are boxed. Species and accession numbers for other bird sequences are as follows: ArciDAB1 Grey Heron, HM991016; ArciDAB2 Grey Heron, HM991017; TyalDAB1 Barn Owl, EU442606; TyalDAB2 Barn Owl, EU442607; ApowDAB01 kiwi, HQ639683, ApowDAB05 kiwi, HQ639685; GagaBLBII chicken, NM_001044679.</p

Schematic illustration of MHC II B genes in the Chinese egret.

<p>Egeu-DAB1, Egeu-DAB2, Egeu-DAB3 and Egeu-DAB4 are labeled as A, B, C and D respectively. Exons are represented in boxes. Functional domains are indicated in light grey. The highly divergent regions encompassing intron 1. LP, leader peptide; TM, trans-membrane domain; CY, cytoplasmic domain.</p

Diversity and selection of MHC class I genes in the vulnerable Chinese egret (<i>Egretta eulophotes</i>)

<div><p>The genes of major histocompatibility complex (MHC) are important to vertebrate immune system. In this study, two new MHC class I genes, designated as Egeu-UAA and Egeu-UBA, were discovered in the vulnerable Chinese egret (<i>Egretta eulophotes</i>). Using a full length DNA and cDNA produced by PCR and RACE methods, these two MHC class I loci were characterized in the genome of the Chinese egret and were also found to be expressed in liver and blood. Both new genes showed the expected eight exons and were similar to two copies of the minimal essential MHC complex of chicken. In genetic diversity, 14 alleles (8 for UAA and 6 for UBA) in the MHC class I gene exon 3 were found in 60 individuals using locus-specific primers and showed little polymorphism. Only three potential amino acid residues were detected under positive selection in potential peptide-binding regions (PBRs) by Bayesian analysis. These new results provide the fundamental basis for further studies to elucidate the molecular mechanisms and significance of MHC molecular adaptation in vulnerable Chinese egret and other ardeids, finding that have not been previously reported.</p></div