BACKGROUND The accurate quantification of antigens at low concentrations over a wide dynamic range is needed for identifying biomarkers associated with disease and detecting protein interactions in high-throughput microarrays used in proteomics. Here we report the development of an ultrasensitive quantitative assay format called immunoliposome polymerase chain reaction (ILPCR) that fulfills the...

The preparation and the properties of gold nanoparticles (Au NPs) protected by perfluorinated amphiphiles are described. The thiols were devised to form a perfluorinated region close to the gold surface and to have a hydrophilic portion in contact with the bulk solvent to impart solubility in water. The monolayer protected clusters were prepared, in an homogeneous phase using sodium thiolates b...

A series of molecular adsorbates having various chain lengths of terminal poly(ethylene glycol methyl ether) (PEG) moieties, thiol head groups, and intervening free radical initiator moieties was used to functionalize the surface of gold nanoparticles (AuNPs). The bulky PEG groups stabilized the functionalized AuNPs by providing steric hindrance against AuNP aggregation, such aggregation being ...

Initially, we asked which (of 10) smooth muscle myosin head residues responds to MgADP or MgATP binding with enhanced fluorescence emission (Trp-441 and Trp-512 were leading candidates)? To decide, we prepared sham-mutated smooth muscle heavy meromyosin (HMM), W441F HMM, and W512F HMM. On adding MgATP, emission of wild-type and W441F HMMs increased by 25-27%, but that of W512F HMM by 5%. So, in...

BACKGROUND Nanobiotechnology can provide more efficient tools for diagnosis, targeted and personalized therapy, and increase the chances of brain tumor treatment being successful. Use of nanoparticles is a promising strategy for overcoming the blood-brain barrier and delivering drugs to the brain. Gelatin-siloxane (GS) nanoparticles modified with Tat peptide can enhance plasmid DNA transfection...

The use of polyethylene glycol (PEG) for precipitation of DNA has been described in the literature (1-6) . We present here conditions for precipitation of DNA by PEG that give improved recoveries of DNA so that precipitation by PEG is comparable to that by ethanol, in terms of recovery, over a wide range of DNA concentrations. The problem of precipitation of lowmolecular-weight DNA fragments by...

INTRODUCTION Polyethylene glycol (PEG) polymers attached to biotherapeutic molecules enhance in vivo delivery and stability of these large molecular weight drugs. However, these polymers may by themselves be immunogenic and elicit antibodies that can reduce the efficacy of the drug and contribute to potential patient morbidity. A double antigen bridging ELISA immunogenicity assay for the detect...

Pregastric esterase (PGE) (EC 3.1.1.3) was purified to homogeneity from calf pharyngeal tissue. The enzyme had an apparent molecular mass of 50 kDa, as determined by SDS/PAGE. The serine-binding reagent diethyl p-nitrophenyl phosphate was a potent inhibitor of PGE. This is in accordance with the claim that a functional serine residue is necessary for the lipolytic activity of lipases. PGE was n...

A mixture of solid KOH in dimethyl sulfoxide has a strong basicity, but only a low nucleophilicity and is used for Q methylation of ketones. With this simple and inexpensive reagent complete methylation with yields up to 90% can be achieved. Solid KOH in dimethyl sulfoxide (DMSO) is a very strong base with a pKa-value of 27 or even higher. l-3 On the other hand, the nucleophilicity of this reag...

We report that a thiol leader peptidase, produced by replacing the critical serine at position 90 with a cysteine residue, is enzymatically active. In contrast to the wild-type leader peptidase, the thiol enzyme can be inactivated with N-ethylmaleimide, a cysteine-specific reagent. This strongly suggests that the serine 90 is involved in catalysis and is located at the active site. Of the three...