23 research outputs found
Crystal structures of the free and anisic acid bound triple mutant of phospholipase A2
Phospholipase A2 catalyses the hydrolysis of the ester bond of 3-sn-phosphoglycerides. Here, we report the crystal structures of the free and anisic acid-bound triple mutant (K53,56,120M) of bovine pancreatic phospholipase A2. In the bound triple mutant structure, the small organic molecule p-anisic acid is found in the active site, and one of the carboxylate oxygen atoms is coordinated to the functionally important primary calcium ion. The other carboxylate oxygen atom is hydrogen bonded to the phenolic hydroxyl group of Tyr69. In addition, the bound anisic acid molecule replaces one of the functionally important water molecules in the active site. The residues 60–70, which are in a loop (surface loop), are disordered in most of the bovine pancreatic phospholipase A2 structures. It is interesting to note that these residues are ordered in the bound triple mutant structure but are disordered in the free triple mutant structure. The organic crystallization ingredient 2-methyl-2,4-pentanediol is found near the active site of the free triple mutant structure. The overall tertiary folding and stereochemical parameters for the final models of the free and anisic acid-bound triple mutant are virtually identical
Integrating Epigenetic Modulators into NanoScript for Enhanced Chondrogenesis of Stem Cells
<i>N</i>-(4-Chloro-3-(trifluoromethyl)phenyl)-2-ethoxybenzamide
(CTB) is a small molecule that functions by altering the chromatin
architecture to modulate gene expression. We report a new CTB derivative
with increased solubility and demonstrate CTB’s functionality
by conjugating it on the recently established NanoScript platform
to enhance gene expression and induce stem cell differentiation. NanoScript
is a nanoparticle-based artificial transcription factor that emulates
the structure and function of transcription factor proteins (TFs)
to effectively regulate endogenous gene expression. Modifying NanoScript
with CTB will more closely replicate the TF structure and enhance
CTB functionality and gene expression. To this end, we first conjugated
CTB onto NanoScript and initiated a time-dependent increase in histone
acetyltransferase activity. Next, because CTB is known to trigger
the pathway involved in regulating <i>Sox9</i>, a master
regulator of chondrogenic differentiation, we modifed a <i>Sox9</i>-specific NanoScript with CTB to enhance chondrogenic gene activity
and differentiation. Because NanoScript is a tunable and robust platform,
it has potential for various gene-regulating applications, such as
stem cell differentiation