🏷️ LIMITED TIME OFFER: GET 20% OFF GRADE+ YEARLY SUBSCRIPTION →
Log in
Biology
1
answer
0
watching
43
views

Describe commercially available recombinant proteins expressedin each of the following expression hosts: E.coli, CHO cells, Sf9cells, Yeast, Plants, and describe the structure and organizationof the vectors used in these various expression systems.

Watch
1
answer
0
watching
43
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Hubert Koch
Hubert KochLv2
28 Sep 2019

Unlock all answers

Get 1 free homework help answer.
Already have an account? Log in
Share

Related textbook solutions

Molecular Cell Biology
8 Edition,
Lodish
ISBN: 9781464183393
Biology: Science for Life with Physiology
6 Edition,
Belk
ISBN: 9780134555430
Biology
2nd Edition, 2013
Openstax
ISBN: 9781947172517
Concepts of Biology
OER Edition,
Openstax
ISBN: 9781938168116
Essentials of Biology
5 Edition,
Mader
ISBN: 9781259660269

Related questions

Expression of a heterologous protein in CHO cells and in an E.coli system produced proteins with the same molecular weight onSDS-PAGE. Subsequent in vitro bioactivity studies demonstratedhigh-level activity with the CHO cell-derived recombinant protein,but no bioactivity with the E. coli derived product. Explain thisdiscrepancy, and propose an experiment to test your hypothesis

a.) Explain the role of positively charge ions (e.g. Ca2+, Li+) used during chemical transformation of E. coli and yeast.

b.) What is the role of i) PEG (Polyethylene glycol) and ii) carrier DNA in yeast transformation?

c.) What is phenotypic expression time in transformation procedure? Explain biological background of it.

d.) Briefly describe two groups of selection markers used for microbial transformation: chemical (antibiotic) resistance and auxotrophic. Explain main principles and selection requirements for each group.

e.) Is phenotypic expression time essential in all transformations? Explain using examples for E. coli ampicillin vs kanamycin, for yeast auxotrophic vs antibiotic resistance markers.

f.) While selecting transgenic plants (Arabidopsis) from transformed seeds, we plated/seeded them directly on selective media plates without phenotypic expression time. However we are looking for antibiotic (hygromycin) resistance. Explain why selection from plant seeds does not require phenotypic expression time.

Using sequence analysis you identify human proteins HKS1 and HKS2, which are most similar to yeast proteins YKS1 and YKS2. In cultures of normal human brain cells, you show that HKS1 and HKS2 localise to vesicles, like HKLP, when transfected with plasmids that express the proteins as GFP fusions. Page 4 You clone the HKS1, HKS2 and HKLP genes into bacterial expression systems that add a hexahistidine tag to their C-termini. Using Ni2+-beads, you purify each of the proteins and use them to raise antibodies in rabbits. You incubate human brain cell extracts with purified HKS2(His)6 and then add Ni2+- beads. You then spin these beads down and analyse the pellets by polyacrylamide gel electrophoresis. Finally you use a western blot to show that HKLP protein is present in the pellet pulled down by HKS2(His)6 bound to Ni2+-beads. When you repeat the experiment in vitro with purified recombinant protein, rather than cell extracts, you find that HKS2(His)6 does not pull down HKLP. You may assume that the hexahistine tag does not interfere with the interactions between proteins.

What is the most likely explanation for why HKS2 might not pull down HKLP in vitro but does so in cell extracts? How might you test this hypothesis with further “pull down” experiments?

Weekly leaderboard

Home
Homework Help 3,900,000
Biology 460,000
Start filling in the gaps now
Log in