BMSC 200 Lecture 4: BMSC 200.3 Notes for Module 4
Document Summary
These include alpha helices and beta sheets: tertiary structure is the complete three- dimensional structure of a polypeptide chain. Some denatured proteins can renature spontaneously to form biologically active protein, showing that protein tertiary structure is determined by primary structure. Collagen polypeptides form left- handed helices and three of these helices wrap around each other in a right- handed coiled- coil. These subunits are stabilized through covalent linkages involving residues which undergo vitamin- c dependent post- translation modifications. Proteins fold by a rapid stepwise process. Some proteins can spontaneously fold to the native conformation; others require the help of chaperone proteins. Fall 2015: protein folding is a rapid process. Some proteins can be renatured. Four levels of protein structure. Fall 2015: conformation: spatial arrangement of groups that are free to assume different positions in space without breaking bonds. Amino acid sequence affects helix stability. Fibrous proteins: keratin, collagen, silk: globular proteins: myoglobin, hemoglobin.
