Exam 21: Biomolecule Purification

Which is NOT true of beads used in chromatography?

Chromatography

Which is NOT true of biotin-avidin interaction?

Resins used in affinity chromatography commonly form weak interactions with atoms important to the ___ structure of proteins.

In size exclusion chromatography I. molecules too large to interact with beads elute in the void volume II. molecules of intermediate size may enter the gel pores and are Retained to a lesser extent than the largest molecules III. beads and buffer together are termed the "bed volume" IV. the elution volume is that at which the targeted protein elutes

Sepharose resin modified with a butyl or phenyl group would be used for

Gradients allow a gradual change in buffer strength, and are convenient, as gradient mixers or pumps can be automated. Gradients are often used for eluting buffers.

At each step of a protein purification scheme, purity should be ascertained by, for example, I. SDS-PAGE gel electrophoresis II. specific activity of antibodies III. western blotting IV. volume measurement

A protein mixture is commonly applied to an HIC column under high ___ conditions, and the protein of interest is eluted with buffer of decreasing ____.

As a successful purification scheme is carried out, the specific activity of a desired enzyme may decrease, though the samples are enriched in the desired enzyme. This is because specific activity is calculated per mg of protein, and often mg protein decreases as the scheme progresses.

Longer size exclusion chromatography columns

Once cells have been lysed, the next step in protein purification commonly includes

With salting in

Analysis of proteins from the inner mitochondrial membrane which are bound to cytochrome groups could likely be facilitated by

Proteins used as drugs are called ___.

By adding increasing amounts of salt to a solution containing proteins, I. the salt causes waters of hydration to form around individual protein Molecules II. salting in occurs, and protein solubility increases III. proteins aggregate at very high salt concentrations IV. at very high salt concentrations, salting out occurs, and protein solubility Increases

Which is NOT a protein molecule used as a pharmaceutical?

Metal affinity chromatography (MAC) commonly uses divalent anions which are bound to a resin. MAC is useful when a protein of interest has an aspartate residue on its surface, which can bind the metal column packing.

Dialysis tubing or bags

Like ion exchange chromatography, MAC