Biochemistry Research

Quantitative Measurement of Biological Substances for Forensic Analysis

Forensics is a growing field that encompasses many specialties and is a career goal for some biochemistry students. Analysis of biochemical molecules can be an important factor in investigations. For example, machines used to count and distribute money may transfer trace levels of cocaine onto bills in general use. Detection of the alkaloid on seized money at levels above an established baseline could be used to support a case against suspected felons. Analytical techniques like High Pressure Liquid Chromatography and Gas Chromatography/Mass Spectrometry can be used to quantitatively measure the amount of cocaine residue on paper currency.  We hope to modify published methods to implement a laboratory experiment for advanced, upper-level biochemistry students to introduce techniques relevant to forensic analysis.

A Novel Assay to Detect Glucosyltransferase Activity in the Presence of Antioxidants

Streptococcus mutans 6715 produces an extracellular enzyme, glucosyltransferase (EC 2.4.1.5) that is responsible for the production of a glucose polymer, a glucan, when in the presence of sucrose. The enzyme glucosyltransferase (GTase) is responsible for the formation of plaque that contributes to dental caries. The enzyme will be isolated and purified from the crude enzyme preparation by centrifugation and dialysis. Further purification will be done by column chromatography.

The goal of this research project is two-fold. One, we will develop an assay to detect enzyme activity different from the current method of an ion-select electrode. We will study, in addition to turbidity, the change in conductivity with polymer formation. Secondly, we will study the effect of an antioxidant on enzyme activity. Kinetic studies will show a change in the Michaelis-Menten constant in the presence of an inhibitor. To follow the kinetics we will use the assay method developed in the first part of the research project.

The Use of Fluorescence to Study Conformation Changes of Enzymes

Optimum enzyme activity is dependent on pH and temperature. This study will examine the affect of these two parameters on the activity of three enzymes, amylase, tyrosinase and phosphatase. A comparison will be made to the fluorescence spectra generated by each of these enzymes to see if the enzymes change conformation when they reach their optimum pH and temperature.