Biochemistry course-based undergraduate research experience: Purification, characterization, and identification of an unknown lactate dehydrogenase isoenzyme

Enzyme purification, characterization, and identification are some of the best ways to introduce undergraduate students to many aspects of biochemistry, particularly as part of project-based learning (PBL). These kinds of multi-step laboratory experiments not only help students to better understand basic biochemistry concepts but also serve to introduce them to the scaffolded nature of the research environment. A 13-week enzyme-based laboratory project was designed as one of three components associated with the course titled Capstone Laboratory, which is delivered to second-year undergraduate students at Weill Cornell Medicine in Qatar (WCM-Q). The project incorporated several fundamental biochemical laboratory techniques, such as chromatography, centrifugation, spectrophotometry, electrophoresis, and kinetic assays, as well as enzyme inhibition and bioinformatic exercises. The aims of the project were to first purify, then to quantify, and finally to study a particular lactate dehydrogenase (LDH) isoenzyme extracted from different chicken organs. LDH was selected for investigation because its inhibition has potential as a therapeutic strategy for cancer treatment. Students enrolled in the Capstone Laboratory course were divided into three groups. Each group conducted experiments associated with one of the project's three aims over consecutive 3-week periods. Relevant data and materials were passed from one group to the next, with individual students writing reports describing the results from their respective collection of experiments. Students in the third and final group gave presentations summarizing the results of the overall project. In the associated bioinformatic exercises, students assessed the similarities and differences between chicken-sourced and human-sourced LDH as well as the interaction between the LDH enzyme and the inhibitors. This PBL in biochemistry is a successful addition to the WCM-Q premedical curriculum because (a) it affords the second-year premedical students opportunities to improve and develop content knowledge and technical and communication skills, and also (b) it provides an opportunity to engage many of the undergraduate students in research.