Biotech Class Notes 10/15/26

Protein Structures

Affinity chromatography is column with a protein that has strong affinity for the column. Everything else ends up going through the column. With E coli, you could use a plasmid that will give us a fusion protein. The fusion protein will stick to the column.

Advantages and Disadvantages of Recombinant Protein Production in E.Coli

Bacteria don’t do the same exact post translational replication. Research advantages and disadvantages for protein production in bacteria.

Protein Expression: Upstream Processing

Best way to transcribe is to get the repressor protein to fall of the operator region of the promoter.?

You need lactose to bind to the protein, change its shape, and cause it fall off. Study fermenters and bioreactors

Fungi

• Some proteins want to use fungi

• They could do the same posttranslational modifications

Plants

• In biotech lab, with plant tissue culture, if tissue culture is use properly, you could have millions of plant protein factories on the field, which makes it easier to find a protein of interest

• Tobacco plants are a model organism since they are the one analyzed the most

• Plats are difficult to work with because of their cell wall

Insect System

• Using live insects to find protein

• We don’t want to kill the damaging insect because the virus could then infect it

Mammalian cell lines still need to be FDA

• Before 1981, if you take a biopsy

Downstream Processing methods:

• Protein purification

Protein purification:

1. Preparing an extract for purification

• Culture medium protein is extracellular: the cells are secreted and this allows the protein to appear

2. Stabilizing proteins in solution

• adding protease inhibitor proteins these from chopping off proteins and promoting growth

• prevent foaming because that is where all the proteins are going to be

3. Methods used for protein separation

• protein precipitation has hydrophilic surfaces but is hydrophobic on the inside

• dialysis is good to get rid of some of those additives

• know different kinds of filtration (faster and cheaper than dialysis tubing)

Watch Video: Ultrafiltratioj

Whatch videos for all related to Exam 2