Pregnenolone activates CLIP-170 to promote microtubule growth and cell migration.

Pregnenolone (P5) is a neurosteroid that improves memory and neurological recovery. It is also required for zebrafish embryonic development. However, its mode of action is unclear.

A new strategy for intracellular delivery of enzyme using mesoporous silica nanoparticles: superoxide dismutase.

We developed mesoporous silica nanoparticle (MSN) as a multifunctional vehicle for enzyme delivery. Enhanced transmembrane delivery of a superoxide dismutase (SOD) enzyme embedded in MSN was demonstrated. Conjugation of the cell-penetrating peptide derived from the human immunodeficiency virus 1 (HIV) transactivator protein (TAT) to mesoporous silica nanoparticle is shown to be an effective way to enhance transmembrane delivery of nanoparticles for intracellular and molecular therapy.

Specifically and reversibly immobilizing proteins/enzymes to nitriolotriacetic-acid-modified mesoporous silicas through histidine tags for purification or catalysis.

Six nitriolotriacetic-acid-modified ordered mesoporous silicas (NTA-OMPSs) with different pore sizes and surface features for specific and reversible protein immobilization were fabricated and characterized. Specific immobilization of a genetically engineered undecaprenyl pyrophosphate synthase (UPPs) from cell lysate and a chemically modified His-tagged horseradish peroxidase (HRP) in these Ni-NTA-OMPSs through histidine coordination to the nickelated NTA was demonstrated and confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and sodium dodecyl sulfate polyacrylamide gel electrophoresis. Negligible leakage of these enzymes over a wide range of acidic conditions was observed.

En route to white-light generation utilizing nanocomposites composed of ultrasmall CdSe nanodots and excited-state intramolecular proton transfer dyes.

One single material that emits white light is of paramount interest for the development of white light-emitting diodes (WLEDs). Here we report a novel nanocomposite, in which a new type of excited-sate intramolecular proton transfer (ESIPT) molecule, namely 5-(1,2-dithiolan-3-yl)-N-(2-{[4-(3-hydroxy-4-oxo-4H-chromen-2-yl)phenyl](methyl)amino}ethyl)pentanamide (HF-N-LA), is anchored onto the surface of ultrasmall CdSe quantum dots through dithiol functionality. Authentic white light with a CIE coordinate of (0.

Pregnenolone stabilizes microtubules and promotes zebrafish embryonic cell movement.

Embryonic cell movement is essential for morphogenesis and the establishment of body shapes, but little is known about its mechanism. Here we report that pregnenolone, which is produced from cholesterol by the steroidogenic enzyme Cyp11a1 (cholesterol side-chain cleavage enzyme, P450scc), functions in promoting cell migration during epiboly. Epiboly is a process in which embryonic cells spread from the animal pole to cover the underlying yolk.