A streamlined molecular biology module for undergraduate biochemistry labs

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.

A 13-week research-based biochemistry laboratory curriculum

Here, we present a 13-week research-based biochemistry laboratory curriculum designed to provide the students with the experience of engaging in original research while introducing foundational biochemistry laboratory techniques. The laboratory experience has been developed around the directed evolution of an enzyme chosen by the instructor, with mutations designed by the students. Ideal enzymes for this curriculum are able to be structurally modeled, solubly expressed, and monitored for activity by UV/Vis spectroscopy, and an example curriculum for haloalkane dehalogenase is given. Unique to this curriculum is a successful implementation of saturation mutagenesis and high-throughput screening of enzyme function, along with bioinformatics analysis, homology modeling, structural analysis, protein expression and purification, polyacrylamide gel electrophoresis, UV/Vis spectroscopy, and enzyme kinetics. Each of these techniques is carried out using a novel student-designed mutant library or enzyme variant unique to the lab team and, importantly, not described previously in the literature. Use of a well-established set of protocols promotes student data quality. Publication may result from the original student-generated hypotheses and data, either from the class as a whole or individual students that continue their independent projects upon course completion. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(5):437-448, 2017.

New ideas for an old enzyme: A short, question-based laboratory project for the purification and identification of an unknown LDH isozyme

Enzyme purification projects are an excellent way to introduce many aspects of protein biochemistry, but can be difficult to carry out under the constraints of a typical undergraduate laboratory course. We have designed a short laboratory project for the purification and identification of an "unknown" lactate dehydrogenase (LDH) isozyme that can fit into a multiproject course without consuming too many laboratory days. The streamlined purification utilizes ammonium sulfate precipitation, affinity chromatography, and size exclusion chromatography to give good recovery of LDH with minimal equipment requirements, and can be completed in three laboratory periods of 3-4 hours. As part of this, we have designed a novel, qualitative format for an LDH activity assay that allows students to rapidly screen their column chromatography fractions without the need of a spectrophotometer or plate reader. The analysis phase of the project is question-driven, and can be completed in two laboratory periods. The students must determine which purification technique was most effective by quantifying LDH activity and total protein content at each step of the purification, and then identify their unknown isozyme through agarose gel electrophoresis. This module provides an engaging format for teaching protein biochemistry, with the flexibility to allow an instructor to modify it for their particular curriculum.