CMB 311 Lecture Notes - Lecture 5: Max Perutz, X-Ray Crystallography, Protein Structure

• School: URI
• Department: Cell and Molecular Biology
• Course: CMB 311
• Professor: Steven Gregory

Document Summary

O2 bidning protein found in muscle, related to hemoglobin. First protein whose 3d structure was determined. Prosthetic groups (cofactors): organic molecules bound to proteins to expand their functional capabilities. Co binds much more tighter than o2 to free heme. Co and o2 both bind much weaker to heme in mb. Reversible binding of ligand (l) to protein (p): p+l pl. Kd is the molar concentration of ligand at which half the available ligand- binding sites are occupied. When l =kd then half the ligand binding sites are occupied. Proteins are not static structures, but are dynamic, exhibiting a range of motions. Dynamic mtions are central to the function of many proteins. Small changes in amino acid sequence can impact conformational dynamics. Protein thermal stability is intimately tied to conformational dynamics. Protein conformational dynamics show a strong temperature dependence. An enzyme can exist in either of two states. R state= relaxed" state, binds substrate more readily.