Learn More
The celB gene of Caldicellulosiruptor saccharolyticus was cloned and expressed in Escherichia coli to create a recombinant biocatalyst for hydrolyzing lignocellulosic biomass at high temperature. The GH5 domain of CelB hydrolyzed 4-nitrophenyl-β-D-cellobioside and carboxymethyl cellulose with optimum activity at pH 4.7-5.5 and 80°C. The recombinant GH5 and(More)
BACKGROUND We have studied the effects of the poly(ethylene glycol) (PEG) chain length and acyl chain composition on the pH-sensitivity of acid-labile PEG-diorthoester (POD) lipids. The optimal conditions are described for preparation of DNA plasmid encapsulated POD nanolipoparticles (NLPs) which mediate high gene delivery activity in vitro with moderate(More)
The effect of folate-targeted liposomal doxorubicin (FTL-Dox) has been well characterized in folate receptor (FR) overexpressing tumors in vitro, particularly in KB human carcinoma cells. However, there are few studies evaluating the in vivo efficacy of FTL-Dox in KB murine xenograft models. In this study, we investigated the antitumor activity of FTL-Dox(More)
High-affinity nitrilotriacetic acids (NTA) have great potential in the molecular manipulation of His-tagged proteins. We have developed a facile method to synthesize multivalent NTA and its conjugates. Starting with appropriately protected lysine, we synthesized the mono-NTA synthons functionalized with either an amino group or a carboxylic group. We then(More)
Nitrilotriacetic acid (NTA) has moderate affinity (10 μM) for hexahistidine (His6) and is widely used in the purification of His6-tagged proteins. The affinity can be increased significantly (10 nM) through multivalency such as using a tris-NTA. We show that the binding affinity of tris-NTA is dependent on the flexibility and length of the spacer between(More)
Metal chelation-ligand interactions, such as occur between nitrilotriacetic acid (NTA)-nickel and multihistidines, enable the noncovalent attachment of histidine-modified proteins to liposomes and other particles. We compared three lipids: a mono-NTA lipid (ca. 10 microM affinity) and two tris-NTA lipid derivatives (ca. 3 nM and 0.2 nM affinity) in their(More)
A series of thiocholesterol-based cationic lipids (TCL) has been designed and synthesized by the attachment of thiocholesterol to a cationic amine via a disulfide bond. TCL can be incorporated into liposomes and used to package DNA into a lipoplex, thereby protecting it from DNase digestion. DNA is rapidly released from the complex in the presence of low(More)
Matrix attachment therapy (MAT) is an enzyme prodrug strategy that targets hyaluronan in the tumor extracellular matrix to deliver a prodrug converting enzyme near the tumor cells. A recombinant fusion protein containing the hyaluronan binding domain of TSG-6 (Link) and yeast cytosine deaminase (CD) with an N-terminal His(x6) tag was constructed to test MAT(More)
Extreme makeover of cholesterol: Cholesterol exchange is a major reason for the instability of liposomes in blood. The formation of a covalent hybrid between cholesterol and glycerophosphocholine preserves the bilayer-stabilizing effect of free cholesterol but prevents its transfer from the bilayer. Thus, disterolphospholipids (e.g. 1) are valuable new(More)
Retinoic acid (RA), the bioactive metabolite of retinol, is essential for robust humoral immunity in animals and humans. Recent interest in RA as a vaccine adjuvant has been encouraged by reports showing cooperative enhancement of antibody responses to tetanus toxin in rodents by all-trans RA (ATRA) and a Toll-like receptor-3 agonist. We hypothesized that(More)