Constructing new bonds to carbon in dihydroquinazolines hypervalent iodine(III)-mediated C(sp)-C(sp) bond functionalization.

A hypervalent iodine(III)-mediated C(sp)-C(sp) bond functionalization reaction for the formation of C-C, C-P, and C-H bonds in dihydroquinazolines has been developed. This one-pot method involves successive oxidation of dihydroquinazoline substrates, mesolytic cleavage of a -butyl substituent, and bond formation to a variety of nucleophiles in moderate to high yields.

Direct Formation of C-C, C-N, and C-O Bonds in Dihydroquinazolines via Hypervalent Iodine(III)-Mediated sp C-H Functionalization.

A hypervalent iodine(III)-mediated cross-dehydrogenative coupling reaction for the direct formation of C-C, C-N, and C-O bonds in dihydroquinazolines has been developed. This one-pot method allows for the synthesis of C4-disubstituted dihydroquinazolines as well as C4-spirolactam, spirolactone, and spiroindene dihydroquinazolines in moderate to high yields.

Evaluation of the efficacy of the Lentulo spiral filler operated at four different speeds and with two different techniques in cadaveric canine teeth of dogs.

This study evaluated the effect of filling technique and rotational speed on the efficacy of sealer cement placement using the Lentulo spiral filler. Cadaveric maxillary and mandibular canine teeth (n = 74) from age and breed matched fresh-frozen adult canine cadaver heads were utilized. Following routine mechano-chemical preparation, teeth were randomly divided into 8 treatment groups with varying rotational speeds [250-2,000 revolutions per minute (RPM)] and fill techniques (backfill technique versus pumping technique).

Homodimeric Granzyme A Opsonizes Mycobacterium tuberculosis and Inhibits Its Intracellular Growth in Human Monocytes via Toll-Like Receptor 4 and CD14.

Mycobacterium tuberculosis (Mtb)-specific γ9δ2 T cells secrete granzyme A (GzmA) protective against intracellular Mtb growth. However, GzmA-enzymatic activity is unnecessary for pathogen inhibition, and the mechanisms of GzmA-mediated protection remain unknown. We show that GzmA homodimerization is essential for opsonization of mycobacteria, altered uptake into human monocytes, and subsequent pathogen clearance within the phagolysosome.

Ube4A maintains metabolic homeostasis and facilitates insulin signaling in vivo.

Objective: Defining the regulators of cell metabolism and signaling is essential to design new therapeutic strategies in obesity and NAFLD/NASH. E3 ubiquitin ligases control diverse cellular functions by ubiquitination-mediated regulation of protein targets, and thus their functional aberration is associated with many diseases. The E3 ligase Ube4A has been implicated in human obesity, inflammation, and cancer.

Endothelial Cell Protein Targeting by Myeloperoxidase-Derived 2-Chlorofatty Aldehyde.

Neutrophils are important cellular mediators of injury and repair in diseases including ischemic heart disease, atherosclerosis, and sepsis. Myeloperoxidase-derived (MPO)-oxidants released from neutrophils are potential mediators of endothelial injury in disease. MPO-derived HOCl attacks plasmalogen phospholipid to liberate 2-chlorofatty aldehyde (2-ClFALD).

Circular permutated red fluorescent proteins and calcium ion indicators based on mCherry.

Red fluorescent indicators for calcium ion (Ca(2+)) are preferable, relative to blue-shifted alternatives, for biological imaging applications due to the lower phototoxicity, lower autofluorescent background and deeper tissue penetration associated with longer wavelength light. Accordingly, we undertook the development of a genetically encoded Ca(2+) indicator based on the popular and widely utilized Discosoma-derived red fluorescent protein, mCherry. Starting from a promising but dimly fluorescent circular permutated variant of mCherry, we first engineered a 13-fold brighter variant (cp196V1.

Mutational analysis of a red fluorescent protein-based calcium ion indicator.

As part of an ongoing effort to develop genetically encoded calcium ion (Ca2+) indicators we recently described a new variant, designated CH-GECO2.1, that is a genetic chimera of the red fluorescent protein (FP) mCherry, calmodulin (CaM), and a peptide that binds to Ca2+-bound CaM. In contrast to the closely related Ca2+ indicator R-GECO1, CH-GECO2.

Circularly permuted monomeric red fluorescent proteins with new termini in the beta-sheet.

Circularly permuted fluorescent proteins (FPs) have a growing number of uses in live cell fluorescence biosensing applications. Most notably, they enable the construction of single fluorescent protein-based biosensors for Ca(2+) and other analytes of interest. Circularly permuted FPs are also of great utility in the optimization of fluorescence resonance energy transfer (FRET)-based biosensors by providing a means for varying the critical dipole-dipole orientation.

Genetically encoded FRET-based biosensors for multiparameter fluorescence imaging.

The phenomenon of Förster (or fluorescence) resonance energy transfer (FRET) between two fluorescent proteins of different hues provides a robust foundation for the design and construction of biosensors for the detection of intracellular events. Accordingly, FRET-based biosensors for a variety of biologically relevant ions, molecules, and specific enzymatic activities, have now been developed and used to investigate numerous questions in cell biology. An emerging trend in the use of FRET-based biosensors is to apply them in combination with a second biosensor in order to achieve simultaneous imaging of multiple biochemical parameters in a single living cell.

Computational prediction of absorbance maxima for a structurally diverse series of engineered green fluorescent protein chromophores.

By virtue of its self-sufficiency to form a visible wavelength chromophore within the confines of its tertiary structure, the Aequorea victoria green fluorescent protein (GFP) is single-handedly responsible for the ever-growing popularity of fluorescence imaging of recombinant fusion proteins in biological research. Engineered variants of GFP with altered excitation or emission wavelength maxima have helped to expand the range of applications of GFP. The engineering of the GFP variants is usually done empirically by genetic modifications of the chromophore structure and/or its environment in order to find variants with new photophysical properties.