Glucose sensors for NMR relaxometry and magnetic resonance imaging (MRI) can be used for the direct measurement of glucose in turbid biological specimens. Here, we proposed a magnetic glucose sensor ...based on superparamagnetic iron oxide (SPIO) nanoparticles conjugated to a mannopyranoside derivative and concanavalin A (ConA). The binding of mannopyranoside groups to ConA produced a nanoparticle cluster that was dissociated by competitive binding of glucose to ConA, resulting in changes in the transverse relaxation time (T2) in a glucose-dependent manner. The sensor gave rise to significant T2 changes in physiological glucose levels of 3 – 8 mM at a nanoparticle concentration of 0.5 nM. Significant T2 responses were observed within 6 min of 5 mM glucose detection. Sensor-based MRI by a benchtop 1 tesla scanner permitted a measurement of multiple samples within 8 min. These results demonstrate that the relaxometric glucose sensor could lead to high throughput direct assay of blood samples by using a compact MRI scanner for point-of-care testing.
A closo-dodecaborate ibuprofen conjugate (DIC) 1 was synthesized via amide bond formation between ibuprofen activated with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI) and ...4-aminoethoxyethoxy-closo-dodecaborate 3 which was synthesized via the ring opening reaction of 1,4-dioxane-closo-dodecaborate complex 2 with ammonia in aqueous solution. DIC showed no significant binding affinity to HSA site 2, which is known as an ibuprofen binding site. DIC accumulated in HeLa cells in a time-dependent manner, and the boron concentration reached 0.68 μg/106 cells 6 h after administration.
Display omitted A closo-dodecaborate ibuprofen conjugate (DIC) 1 was synthesized and evaluated for albumin binding assay and cell-uptake using HeLa cells.
•A closo-dodecaborate ibuprofen conjugate (DIC) 1 was synthesized.•DIC accumulated in HeLa cells in a time-dependent manner.•DIC showed no significant binding affinity to the ibuprofen binding site of HSA.
Dragline silk of golden orb-weaver spiders (Nephilinae) is noted for its unsurpassed toughness, combining extraordinary extensibility and tensile strength, suggesting industrial application as a ...sustainable biopolymer material. To pinpoint the molecular composition of dragline silk and the roles of its constituents in achieving its mechanical properties, we report a multiomics approach, combining high-quality genome sequencing and assembly, silk gland transcriptomics, and dragline silk proteomics of four Nephilinae spiders. We observed the consistent presence of the MaSp3B spidroin unique to this subfamily as well as several nonspidroin SpiCE proteins. Artificial synthesis and the combination of these components in vitro showed that the multicomponent nature of dragline silk, including MaSp3B and SpiCE, along with MaSp1 and MaSp2, is essential to realize the mechanical properties of spider dragline silk.
Niemann‐Pick disease type C (NPC) is a genetic disorder in which patient cells have endosomal/lysosomal accumulation of cholesterol and sphingolipids. However, the relationship between sphingolipids ...and cholesterol accumulation in NPC cells has not been established. Here, we investigated the role of sphingomyelin (SM) on the accumulation of cholesterol in NPC cells. Reduction of SM by inhibition of the ceramide transfer protein CERT decreased the cholesterol accumulation in NPC cells. The accumulation of SM in NPC cells inhibited the transport of cholesterol to the endoplasmic reticulum. Overexpression of Rab9 in NPC cells reduced the cholesterol accumulation, which was recovered by treatment with SM. In NPC cells that overexpressed a Rab9 constitutively active mutant, SM treatment did not lead to the cholesterol accumulation. These results indicate that SM negatively regulates the Rab9‐dependent vesicular trafficking of cholesterol, and a reduction in SM levels in NPC cells recovers the Rab9‐dependent vesicular trafficking defect.
We found that sphingomyelin (SM) inhibited vesicular trafficking between the late endosome and the Golgi, which accelerated the accumulation of cholesterol in Niemann‐Pick disease type C (NPC) cells. We found that a reduction in SM levels in NPC cells decreased the accumulation of cholesterol by improving cholesterol vesicular trafficking.
New matrix metalloproteinase 1 (MMP-1) inhibitors were predicted using the structure-activity relationship (SAR) transfer method based on a series of analogues of kinesin-like protein 11 (KIF11) ...inhibitors. Compounds 5-7 predicted to be highly potent against MMP-1 were synthesized and tested for MMP-1 inhibitory activity. Among these, compound 6 having a Cl substituent at the R
site was found to possess ca. 3.5 times higher inhibitory activity against MMP-1 than the previously reported compound 4. The observed potency was consistent with the presence of an SAR transfer event between analogous MMP-1 and KIF11 inhibitors. Pharmacophore fitting revealed that the higher inhibitory activity of compound 6 compared to compound 4 against MMP-1 might be due to a halogen bond interaction between the Cl substituent of compound 6 and residue ARG214 of MMP-1.
After uptake by U87 MG and A375 cancer cells, cobaltabisdicarbollide COSAN− distributes between membrane and nucleus and presents no relevant cytotoxicity against both cell lines even for long ...incubation times. The cytotoxicity of NaCOSAN was also tested towards one normal cell line, the V79 fibroblasts, in order to ascertain the noncytotoxic profile of the compound. As the cell's nucleus contains DNA, the interaction between COSAN− and double‐stranded calf thymus DNA (CT‐dsDNA) has been investigated. There is a strong interaction between both molecules forming a nanohybrid CT‐dsDNA‐COSAN biomaterial, which was fully characterized. Moreover, NaCOSAN shows characteristic redox peaks ascribed to the oxidation/reduction of Co3+/2+ at a formal potential of −1.444 V and it can be accumulated at a surface‐immobilized DNA layer of glassy carbon electrodes. The equilibrium surface‐binding constants (Kox/Kred), which confirm that COSAN− interacts with DNA by an intercalative or electrostatic mode, depending on the ionic strength of the solution, were estimated. In addition, high binding affinity of NaCOSAN to proteins was observed by 11B{1H} NMR and confirmed in vivo. Finally, biodistribution studies of COSAN− in normal mice were run. After administration, NaCOSAN was distributed into many organs but mainly accumulated in the reticuloendothelial system (RES), including liver and spleen. After 1 h, the formation of aggregates by plasma protein interaction plays a role in the biodistribution profile; the aggregates accumulate mostly in the lungs. NaCOSAN, which displays low toxicity and high uptake by relevant cancer cells accumulating boron within the nucleus, could act as a suitable compound for further developments as boron neutron capture therapy (BNCT) agents.
Bioactive metallacarborane: The noncytotoxic profile of Na3,3′‐M(1,2‐closo‐C2B9H11)2, COSAN−, has been demonstrated on V79 fibroblast cells and its biodistribution in normal mice reported. Pristine COSAN− molecules enter the cytoplasm of the cell and reach the nucleus. The strong interaction between NaCOSAN and double‐stranded calf thymus DNA (CT‐dsDNA) has been revealed (see graphic) and the formed nanohybrid biomaterial fully characterized.
Mimicking bioactive conformations of peptide segments involved in the formation of protein-protein interfaces with small molecules is thought to represent a promising strategy for the design of ...protein-protein interaction (PPI) inhibitors. For compound design, the use of three-dimensional (3D) scaffolds rich in sp3-centers makes it possible to precisely mimic bioactive peptide conformations. Herein, we introduce DeepCubist, a molecular generator for designing peptidomimetics based on 3D scaffolds. Firstly, enumerated 3D scaffolds are superposed on a target peptide conformation to identify a preferred template structure for designing peptidomimetics. Secondly, heteroatoms and unsaturated bonds are introduced into the template via a deep generative model to produce candidate compounds. DeepCubist was applied to design peptidomimetics of exemplary peptide turn, helix, and loop structures in pharmaceutical targets engaging in PPIs.
Intracellular photocatalytic-proximity labeling (iPPL) was developed to profile protein-protein interactions in the microenvironment of living cells. Acriflavine was found to be an efficient ...cell-membrane-permeable photocatalyst for introduction into the genetically HaloTag-fused protein of interest for iPPL with a radical labeling reagent, 1-methyl-4-arylurazole. iPPL was applied to the histone-associated protein H2B in HaloTag-H2B expressing HEK293FT cells. The proteins directly interacting with histones and RNA-binding proteins were selectively labeled in the intracellular environment, suggesting that the iPPL method has a smaller labeling radius (
6 nm) than the BioID and APEX methods.
Abstract
Comparing newly obtained and previously known nucleotide and amino-acid sequences underpins modern biological research. BLAST is a well-established tool for such comparisons but is ...challenging to use on new data sets. We combined a user-centric design philosophy with sustainable software development approaches to create Sequenceserver, a tool for running BLAST and visually inspecting BLAST results for biological interpretation. Sequenceserver uses simple algorithms to prevent potential analysis errors and provides flexible text-based and visual outputs to support researcher productivity. Our software can be rapidly installed for use by individuals or on shared servers.
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