BIOLOGY 173 Lecture Notes - Lecture 6: Column Chromatography, Ampicillin, Catechol
Document Summary
A cell extract containing many different proteins is loaded on a column containing a bead matrix. Some proteins stick to the beads while others pass through (are eluted from the column). In a second pass, conditions can be changed, so that some proteins no longer stick to the beads and will be eluted. This can be repeated many times, e. g. , changing salt concentration in small steps, to divide the original extract into many fractions. (goal: end up with solely strong catechol binding proteins) Under regular salt conditions, gfp will fold so that its hydrophobic residues face inward and do not interact with water. For gfp, this means its hydrophobic residues are now exposed. If denatured gfp is passed over a column with hydrophobic beads, it will stick to them strongly. As salt concentration is lowered, gfp will return to its normal folding and no longer stick to beads.
