Recent proteomic studies have led scientists to estimate that there are almost a million different proteins in a single human cell. The function and properties of these proteins are highly distinct ranging from structural proteins involved in cell integrity, including hydrophobic cell membrane proteins, to soluble signal proteins that are responsible for passing cellular messages from the cell membrane to the nucleus. A major property of proteins that determines their function and location is their solubility within a cell. There are two major classes; the hydrophobic (water-“scared”) and hydrophilic (water-“friendly”) proteins.
This lab activity is designed to demonstrate the different classes of protein molecules and their classification based on solubility. Students learn fractionation of soluble, insoluble membrane proteins, and cytoskeleton proteins from a tissue sample. The insoluble protein fraction is further fractionated into hydrophilic and hydrophobic membrane proteins. Cell membrane structure and the role of hydrophobic membrane proteins are considered. This lab activity also provides an opportunity to understand characteristics of various classes of detergents and the role of detergents in solubilization of hydrophobic membrane proteins.
Supplied with components needed for hands-on experimentation for six workstations of 4-5 students or 24-30 students. Supplied with Teacher’s Guide and separate Student’s Guides.
Applications
This kit teaches the following:
- Different classes of proteins based on solubility.
- Solubilization of proteins and role of detergents.
- Characteristics of detergents in aqueous solution.
- Hydrophilic and hydrophobic proteins.
- Membrane proteins and structure of membranes.