Denise Laspina

A method is described for using custom snap-on lids to protect chemicals in microtiter plates from evaporation and contamination. The lids contain apertures (diameter 1.5, 1.0, or 0.5 mm) through which the chemical building blocks can be transferred. The lid with 0.5 mm apertures was tested using a noncontact acoustic liquid handler; the 1.0 and 1.5 mm lids were tested using two tip-based liquid handlers. All of the lids reduced the rate at which solvents evaporated to room air, and greatly… Show more

A method is described for using custom snap-on lids to protect chemicals in microtiter plates from evaporation and contamination. The lids contain apertures (diameter 1.5, 1.0, or 0.5 mm) through which the chemical building blocks can be transferred. The lid with 0.5 mm apertures was tested using a noncontact acoustic liquid handler; the 1.0 and 1.5 mm lids were tested using two tip-based liquid handlers. All of the lids reduced the rate at which solvents evaporated to room air, and greatly reduced the rate of contamination by water and oxygen from room air. In steady-state measurements, the lids reduced the rate of evaporation of methanol, 1-hexene, and water by 33% to 248%. In cycled experiments, the contamination of aqueous solvent with oxygen was reduced below detectability and the rate at which DMSO engorged atmospheric water was reduced by 81%. Our results demonstrate that the lids preserve the integrity of air-sensitive reagents during the time needed for different types of liquid handlers to perform dispensations. Controlling degradation and evaporation of chemical building blocks exposed to the atmosphere is increasingly useful as the reagent volume is reduced by advances in liquid handling technology, such as acoustic droplet ejection. Show less

We used high throughput screening using X-ray diffraction to identify a novel ligand for bovine superoxide dismutase (SOD). The ligand observed bound to SOD’s active site however we postulate that a ligand bound in the extended lateral cleft distal to the SOD active site would be a therapeutically relevant location. Many mutations that induce familial amyotrophic lateral sclerosis (ALS) occur on this extended beta sheet region. We believe that interactions between SOD monomers may cause disease… Show more

We used high throughput screening using X-ray diffraction to identify a novel ligand for bovine superoxide dismutase (SOD). The ligand observed bound to SOD’s active site however we postulate that a ligand bound in the extended lateral cleft distal to the SOD active site would be a therapeutically relevant location. Many mutations that induce familial amyotrophic lateral sclerosis (ALS) occur on this extended beta sheet region. We believe that interactions between SOD monomers may cause disease like symptoms. If this hypothesis is correct, then any ligand that binds tightly to this region may prevent or even reverse disease symptoms. It is also possible that wild type ALS patients (which account for 80% of ALS incidence) would benefit through a similar therapeutic mechanism (if the disease causing mechanism is the same, as seems likely). We began our investigation by identifying a novel overnight crystallization condition for SOD which yields well diffracting crystals (1.1Å) using as little as 2.5 nL of protein and precipitant. Our crystals were robust enough to endure extended soaking or co-crystallization with several fragment libraries, including both fragment cocktails and one-at-a time libraries. Show less