Chemistry: Advanced Biochemistry

KEMM23. Membrane proteins are absolutely necessary for the energy metabolism of the cell and for its ability to sense and communicate with its environment. About half of all pharmaceutical drugs used today target membrane bound proteins. In this course you will learn more about different types of membrane proteins, how they can be overexpressed and purified from a host cell and how different methods can be used to analyse their structure and function. The course includes predictions and practical investigations of protein folding in a membrane, as well as a shorter project where you under guidance plan and carry out cloning and overexpression of a membrane protein of your choice.

Course content

Lectures: The lectures address the three different main types of membrane proteins and associated cellular processes: transport and transporters, signal transduction and receptors, bioenergetics and photosynthetic and respiratory proteins. A number of proteins from each process, for which the structure is known, are explored in greater detail in order to highlight the functional molecular mechanisms. Lectures dealing with methods for theoretical modelling of membrane protein structure, fusion protein techniques, X-ray crystallography, heterologous expression, solubilisation and purification of membrane proteins are also included in the course.

Laboratory sessions, exercises and project work: Determination of the transmembrane topology of a protein starts with a model of the protein bases on sequence information and theoretical methods. This is followed by experimental determination using genetic construction and expression of a fusion protein of the membrane protein and a marker protein in a bacterial system which is subsequently analysed.

In silicon exercise addressing potential problems concerning the detection of heterologously expressed membrane proteins, solubilisation and evaluation of detergent properties, ion exchange chromatography and gel filtering in the presence of a detergent, and control of the protein's stability and integrity after purification.

An individually planned and executed minor project during two weeks, in which the students express a membrane protein of their choice and demonstrate in some way that the expression was successful. The project entails practice in literature searching, project planning and documentation, and provides specialised practical knowledge of expression and management of membrane proteins. The project is to be concluded with a poster presentation.