Module Information

The course is designed to extend and reinforce those aspects of protein structure dealt with in the first year with current ideas on the folding of nascent proteins and the post-translational modifications, to give the students a firm understanding of the relationship between structure and function.

The module begins with a survey of the wide range of protein function with examples given for each. The next section deals with protein structure starting with the amino acid building blocks with a reminder of the importance of pH in the role of charged groups in protein structure and function.

The structure of some biologically active small peptides are described before the course moves on to deal with the polypeptides as found in proteins and considers their primary structure and its elucidation. The students will be reminded of the special features of the peptide bond that lead to secondary structure and of the main types of secondary structure, a-helix, b-pleated sheet and the collagen triple helix. This leads on to a consideration of tertiary and quaternary structures, their stabilisation and importance to function, with haemoglobin used as the main example. The process of protein folding to give a functional structure and the way in which proteins are targeted to cell compartments will be described. Aspects of post-translational modification of proteins will also be dealt with.

Several lectures will cover basic aspects of catalysis, enzyme nomenclature, enzyme assay, simple enzyme kinetics, inhibition of enzymes and some aspects of control. The ways in which enzymes might bring about catalysis are examined with a more detailed look at chymotrypsin to illustrate these points.

The final section deals with aspects of protein purification. Procedures for estimation of protein purity and the protocol for documentation of a purification are described.

As part of their individual studies the students are expected to work through the chapters on pH in the appropriate textbooks and to become familiar with calculations in this topic by attempting the numerical problems at the end of these chapters. Further individual study may be supplemented by on-line tutorials and testing provided by the text associated with Stryer, see below. Students are also expected to familiarise themselves in this way with quantitative aspects of enzyme assays, particularly by use of spectrophotometry, and enzyme kinetics.