March 7, 2013
Mr. Michael Molnar
Acrylodan Labeled Human Serum Albumin Behaviors in Denaturing Surfactants
Abstract: The study of biomolecules in ionic liquids (ILs) has become of interest because of properties such as ionic strengths and varying viscosities the ionic liquids possess in solutions. Some studies have focused on the use of an enzyme that went through physical changes due to the ILs, which is important for any protein to function properly. To determine the affect of the blood protein human serum albumin (HSA), HSA was chemically labeled by covalent attachment with a single fluorophor, acrylodan (Ac). HSA-Ac was then dissolved in phosphate buffered saline (PBS) or 1-butyl-3methylimidazolium ionic liquids with varying anions. Since Ac was covalently attached to cysteine-34 of HSA, the focuses of the chemical reactions were on loop 1 of domain 1. HSA’s physical resistance properties to temperature and ionic strengths where tested at varying temperatures in both PBS and 1-butyl-3methylimidazolium ionic liquids. Upon increasing temperature, hydrophobic amino acids and the IL became strongly associated. When heated, HSA in both PBS and IL denatured, and showed marked deviations from native HSA. The data showed further that subsequent addition of deionized water to the denatured protein solution caused renaturation. The study of HSA in ILs has helped understand the physical resistance properties of HSA when ILs and PBS are present.
Ms. Joshua Burgmeier
Firefly Luciferase Stabilized in [TMG][AC] Ionic Liquid
Abstract: Luciferase is an enzyme used in many organisms to catalyze a light-producing chemical reaction. Bioluminescence involves oxidizing the substrate luciferin, ultimately resulting in an excited-state product, which produces light when the product relaxes back to the ground state. Luciferase is applied in many ways in the field of biotechnology, especially as a reporter gene, and the possibilities will be broadened if the enzyme is made more thermally stable. One method to stabilize proteins currently being studied is the use of ionic liquid mediators. This study examines the effects of three 1,1,3,3-tetramethylguanidine [TMG] based ionic liquids on the activity and stability of photinus pyralis luciferase. In the presence of [TMG][acetate], the thermal stability and activity of the enzyme was improved significantly, including a reduction of Km for ATP. However the other ionic liquids, [TMG][triflouroacetate] and [TMG][trichloroacetate], decreased or had an insignificant impact on thermal stability and activity. The results of this study provide an option for stabilizing this enzyme as well as add data to the ongoing effort to study ionic liquids, their properties, and their effect on enzymes and other proteins.