Youngmi Kim

A CF3-BODIPY forms strongly luminescent aggregates, which contrasts with the quenched condensed-phase photophysics that are typical for BODIPY dyes. Examination of the luminescent properties of these aggregates – narrow red-shifted absorption and emission bands, minimal Stokes shift and increased fluorescence rate constants – and of the solid-state packing of the dye establish the CF3-BODIPY as the first structurally characterized genuine BODIPY J-aggregate.

Here we report the inhibition of cellular invasion by a recombinant mouse endostatin and the possible mechanism of the inhibition. Endostatin significantly reduced endothelial as well as tumor cellular invasion into the reconstituted basement membrane in vitro. Gelatin zymographic analysis revealed that the activation of promatrix metalloproteinase-2 (proMMP-2) that was secreted from endothelial cells was blocked upon endostatin treatment. Studies with recombinant MMPs confirmed that endostatin

It is theorized that multivalent interaction can result in better affinity and selectivity than monovalent interaction in the design of high-performance ligands. Accordingly, biomolecular engineers are increasingly taking advantage of multivalent interactions to fabricate novel molecular assemblies, resulting in new functions for ligands or enhanced performance of existing ligands. Substantial efforts have been expended in using small molecules or epitopes of antibodies for designing multifuncti

Liquid hot (LHW) water pretreatment (LHW) of lignocellulosic material enhances enzymatic conversion of cellulose to glucose by solubilizing hemicellulose fraction of the biomass, while leaving the cellulose more reactive and accessible to cellulase enzymes. Within the range of pretreatment conditions tested in this study, the optimized LHW pretreatment conditions for a 15% (wt/vol) slurry of hybrid poplar were found to be 200(o)C, 10 min, which resulted in the highest fermentable sugar yield wit

Fluorescent probe 1, showing a high fluorescence turn-on signal ratio, enables the real-time imaging of endogenous alkaline phosphatase (ALP) activity in living cells, and the fast and quantitative analysis of enzyme activity at the single-cell level.

A highly selective fluorescent probe for a protein tyrosine phosphatase (PTP) was designed by a simple phosphorylation of the 2-(2'-hydroxyphenyl)benzothiazole (HBT) chromophore: upon selective enzymatic hydrolysis, an excited-state intramolecular proton transfer (ESIPT) occurs, resulting in a large Stokes shift.

The ability to inhibit an enzyme in a specific tissue with high spatial resolution combined with a readily available antidote should find many biomedical applications. We have accomplished this by taking advantage of the cis-trans photoisomerization of azobenzene molecules. Specifically, we positioned azobenzene moieties within the DNA sequence complementary to a 15-base-long thrombin aptamer and then linked the azobenzene-modified cDNA to the aptamer by a polyethylene glycol (PEG) linker to mak

Fundamental characterization of pretreated hardwood and its interactions with cellulolytic enzymes has confirmed that a pathway exists for dramatically reducing the loading of cellulase required for hydrolysis of pretreated biomass. We demonstrate that addition of protein effecting a seven-fold decrease in the specific activity of cellulases enables a ten-fold reduction in enzyme loading while maintaining a high level of cellulose hydrolysis in pretreated hardwood. While use of protein and other

A boronate-based fluorescent probe 1 for the selective monitoring of intracellular peroxynitrite has been developed. The probe takes advantage of the fast reaction of an arylboronate group with peroxynitrite, yielding a corresponding phenol that undergoes spontaneous subsequent reactions to produce a strongly fluorescent product associated with a large turn-on signal.

Conjugated polymers often display a decrease of fluorescence efficiency upon aggregation due in large part to enhanced interpolymer interactions that produce weakly emissive species generally described as having excimer-like character. We have found that poly(phenylene ethynylene)s with fused pendant [2.2.2] ring structures having alkene bridges substituted with two ester groups function to give highly emissive, broad, and red-shifted emission spectra in the solid state. To best understand the o

Single stage and multi-stage liquid hot water pretreatments of mixed hardwood pinchips were investigated at various severities (log R0 = 3.65-4.81) to assess the efficiencies of the pretreatments with respect to achieving high pentose sugar yields and improved enzymatic digestibility of pretreated cellulose. We investigate the effect of pretreatment parameters that is, temperature, and time, as expressed in the severity factor, on the recovery of sugars and hydrolyzability of pretreated cellulos

Stress light up! Methyl thio-BODIPY 2 detects hypochlorous acid on the basis of the selective oxidation of its methylthioether group into the corresponding sulfoxide by the analyte, resulting in a strong fluorescence turn-on signal. Reactive oxygen species (ROS) are essential for a wide range of biological and pathological events.1 During infection and inflammation, the phagocytic leukocytes, including neutrophils, monocytes, and macrophages generate reactive oxygen species (ROS) to kill invadin