Crystallization of Lactobacillus helveticus PEPX
Faculty Sponsor
Deanna Ojennus, Whitworth University
Research Project Abstract
X-Prolyl amino dipeptidase (PEPX), an enzyme involved in the removal of N-terminal amino acids that are adjacent to a penultimate proline residue, was isolated from Lactobacillus helveticus, lactic acid producing bacterium. PEPX protein suitable for crystallization was expressed using an E. coli pET expression system followed by cell lysis, ammonium sulfate precipitation, and purification by affinity and ion exchange HPLC. PEPX protein crystals were obtained with 7.4 mg/ml protein and 6-8% PEG stock and 75-100 mM Kpi pH 6.0 buffer solution. The enzyme was successfully crystallized by hanging drop crystallization methods. Solving the three-dimensional structure of a protein will allow for better understanding of its mechanism and function.
Session Number
PS1
Location
Graves Gym
Abstract Number
PS1-l
Crystallization of Lactobacillus helveticus PEPX
Graves Gym
X-Prolyl amino dipeptidase (PEPX), an enzyme involved in the removal of N-terminal amino acids that are adjacent to a penultimate proline residue, was isolated from Lactobacillus helveticus, lactic acid producing bacterium. PEPX protein suitable for crystallization was expressed using an E. coli pET expression system followed by cell lysis, ammonium sulfate precipitation, and purification by affinity and ion exchange HPLC. PEPX protein crystals were obtained with 7.4 mg/ml protein and 6-8% PEG stock and 75-100 mM Kpi pH 6.0 buffer solution. The enzyme was successfully crystallized by hanging drop crystallization methods. Solving the three-dimensional structure of a protein will allow for better understanding of its mechanism and function.
