Biochemistry 2280A Lecture Notes - Lecture 4: Immunoglobulin Light Chain, Protein Precursor, Molecular Machine
30 Jan 2018
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Unit 1: fundamental concepts of biochemistry lesson 4: protein function and enzymes (sept. 19th/21st 2017) Post-translational modifications: phosphorylation, ubiquitination, acetylation, sumoylation alters stability or signalling, glycosylation affects protein folding, secretion, solubility, binding to other biomolecules, myristoylation, farnesylation alters location, metalloproteins bind metal ions, hemoproteins have an attached heme group. Lives its life outside the cell: collagen molecule joins with others to made a fibril, attach end to end and well as side to side. Collagen properties: thin (1. 5nm), long (300nm), very strong molecule, hydrophobic, insoluble due to the exposed side chains, has to be first synthesized as precursor containing pro-peptides which keeps it soluble. Called pro-collagen: pro-peptides increase solubility and prevent premature fibre formation. Collagen assembly: pro-collagen secreated from cell, removed before fibril assembly, collagen molecules are covalently cross-linked in the fibril, lysine residues in different chains, gives further strength to the fibril, glycosylation facilitates extracellular solubility as well as water absorption. Immune response is triggered by foreign macromolecules (antigens).
