Structure and function are correlated at all levels of biology. This topic is typically addressed early in an undergraduate class in general or molecular biology before students have gained much skill or knowledge in molecular biology. However, an understanding of the chemical bonds involved in forming and maintaining the structure of proteins is critical to understanding how enzymes function and how their activity can be regulated. Here, a laboratory activity is described that is suitable for undergraduate biology students. This activity examines the activity of carboxypeptidase A (CPA), an abundant pancreatic enzyme with a rich history in enzymology and structural biology. The abundance of CPA in pancreatic tissue allows for a series of common biochemical techniques to be easily performed under the constraints of an undergraduate teaching lab, including the separation of proteins by simple precipitation methods, the examination of resulting proteins by SDS-PAGE and Coomassie staining, and the analysis of enzyme function through the determination of constants such as Vmax and Km. These steps illustrate the importance of noncovalent bonds in protein structure and the use of common biochemical instruments in the lab, while providing students with an opportunity to hone analysis skills in their consideration of the resulting data. Finally, this lab may be modified in many ways to make it suitable for upper division classes, CURE approaches to the undergraduate lab, and even to the pre-college classroom.

Primary Image: Carboxypeptidase structure and function. The crystal structure of a human homolog (CPA2; PDB ID 1AYE; image created in PyMol) of carboxypeptidase A is shown. The prodomain is at the top left and the enzymatic domain is below, with the required zinc in the active site shown as a gray sphere. Cleavage of a synthetic substrate by carboxypeptidase A can be seen using a spectrophotometer as a decrease in absorbance.

Immunology is relevant to our everyday lives, driving a need for more engaging and inclusive undergraduate immunology education. One way to engage a diverse group of learners is by teaching them how to read and interpret the scientific literature. This introduction can be challenging for immunology research, which often includes jargon and significant background information. The lesson described here meets this challenge by first teaching students the basics of reading a journal article. Students then read a seminal research article in the field and discuss the data and conclusions via think-pair-share in the classroom. This lesson teaches students the overall structure of a journal article, how to read a journal article, and the ability to read and interpret a research article’s findings. Additionally, students learn specifically about the organization and expression of the genes encoding B-cell receptors.

Primary Image: Image portrays the computer a student will use to read the literature while thinking about the B-cell receptor (shown here in secreted form as antibodies). Image was created using BioRender.