IL-13 - York College of Pennsylvania
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Transcript IL-13 - York College of Pennsylvania
Design and Production of a GFP and Human IL-13
Linked Chimeric Protein in E. coli Using pQE-30 Vector
Stephen R. Suknaic
Department of Biology, York College of Pennsylvania
Structure of GFP
Structure of IL-13
Introduction
Methods
Results
Conclusions
Interleukin 13 (IL-13) is an immunoregulatory cytokine that has been a
useful tool in breast and brain cancer
research (Kawakami 2004). This protein is
a ligand for the surface receptors IL13Rα1 and IL-13Rα2. These receptors are
effective targets for cancer research due
to their over-expression on the surface of
certain cancer cell types.
This project began with the design of a
protein with the following structure:
The following amino acid sequence
was inferred from the final pQE-30 DNA
sequence
obtained
from
Elim
Biopharmaceuticals:
All the amino acid codons for GFP
IL-13 ligand has been experimentally
attached to other proteins to produce a
new fusion or ‘chimera’ protein. By
successfully developing a fused protein
consisting of more than one active part,
researchers
have
been
able
to
successfully develop a single protein with
multiple functions and potential uses. A
prime example of this is a fusion of IL-13
and Pseudomonas exotoxin A, which
can carry a toxic molecule to a cell
expressing the IL-13 receptor.
The
primary
objective
of
this
experiment is to see if IL-13 could be
successfully fused with Green Fluorescent
protein to create a green glowing
chimera protein containing the IL-13
ligand. Such a protein would have many
theoretical uses:
Competition
assays
with
targeting the IL-13Rα2 Receptor
drugs
Quantification of the number of IL-13
receptors on a cell membrane
Luminescence can be used to identify
tumor locations or sizes
His-Tag and
Entero-kinase
Cut Site
GFP
Linker Region
and Factor
Xa Cut Site
IL-13
The following timeline is a summary of the
protocols involved with this experiment:
Designed Primers for GFP and IL-13
PCR Amplified Stock DNA for GFP and
IL-13 Using Custom Primers
Digestion and Ligation of GFP DNA and
pQE-30 Vector with Restriction Enzymes
Verify Construct with DNA Sequencing
Transformation of GFP/pQE-30 Vector
into Competent E. coli
Harvested and Purified Plasmid
from Transformed E. coli
Histidine Tag
GFP
Factor Xa Cut Site
Enterokinase Cut Site
Linker Region
IL-13
Modified
pQE-30
successfully created
produce chimera
vector
was
and used to
The proper structure of this protein
was confirmed by protease digests, Ionaffinity chromatography, and presence
of the characteristic glow of Green
Fluorescent Protein
Take Home Message
Histidine Tag presence and function
was verified by testing the chimera for
affinity to Nickel- ion beads using IMAC
The GFP and IL-13 chimera was
successfully made using the pQE-30
vector as a means to transform E. coli
Enterokinase Cut Site presence was
confirmed by treatment with Enterokinase
enzyme to release the protein from the
beads
The components of this protein were
tested to confirm their presence
beyond just their amino acid sequence
Digested Recovered Plasmid and
IL-13 DNA with Restriction Enzymes
GFP presence was confirmed by the
characteristic bright green glow
Future studies could test to see if the
chimera will bind effectively to the IL-13
α1 and/or α2 receptor
Ligation of IL-13 DNA into Vector
Linker Region presence was confirmed
by the DNA sequencing
Works Cited
Vector Transformation into
Competent E. coli
Grow to O.D. 600 ≈ 1.0 Abs
Induced Protein Production with
IPTG Treatment
Harvested E. coli and lysed
with B-per Reagent
Purified Inclusion Body and Isolated
Chimera via Ion-Affinity Chromatography
Primary Objectives
I. Integrate modified DNA sequences for
GFP and IL-13 into pQE-30 vector
Factor Xa Cut Site presence was
confirmed by treatment of the chimera
with Factor Xa enzyme
IL-13 presence was supported by the
polyacrylamide gel run after the Factor
Xa enzyme treatment
Figure 1: Structure of the Quiagen pQE-30 Vector
GFP and
Linker ~30 kd
Intact
Chimera
~42 kD
kD
50
37
25
20
Factor Xa
enzyme
15
10
IL-13 ~12 kd
1
II. Transform said vector into competent
E. coli and induce protein production
with IPTG
III. Isolate chimera and analyze it for
proper biological activity
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nilghkleynynshnvyitadkqkngikanfkirhniedgsvqladhyqqn
tpigdgpvllpdnhylstqsalskdpnekrdhmvllefvtaagithgmdel
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vwsinltagmycaaleslinvsgcsaiektqrmlsgfcphkvsagqfsslhv
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and IL-13 were properly integrated in
sequence into the pQE-30 vector
2
3
4
Figure 2: Polyacrylamide gel showing the intact chimera as
well as after digestion with Factor Xa enzyme. The IL-13 that
was digested is running at ~12 kD. Lane 1 contained standard
kaleidoscope ladder. Lane 2 contained only the purified
chimera with a mass of ~42kD. Lane 3 contained the chimera
digested with Factor Xa enzyme. Lane 4 contained only the
Factor Xa enzyme.
Kawakami K, Kawakami M, Puri RK. Specifically targeted
killing of interleukin-13 (IL-13) receptor-expressing breast
cancer by IL-13 fusion cytotoxin in animal model of human
disease. Molecular Cancer Theory. 2004 Feb;3(2):137-47.
Kawakami K, Kawakami M, Puri RK. IL-13 receptortargeted cytotoxin cancer therapy leads to complete
eradication of tumors with the aid of phagocytic cells in
nude mice model of human cancer. Journal of
Immuonology. 2002 Dec 15;169(12):7119-26
http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=S
howDetailView&TermToSearch=3596
http://www.conncoll.edu/ccacad/zimmer/GFPww/structure.html
http://www.rcsb.org/pdb/explore/images.do?structureId=1I
JZ
http://www1.qiagen.com/Products/Protein/Expression/QIAe
xpressExpressionSystem/pQE-30XaVector.aspx?ShowInfo=1
Acknowledgements
I would like to thank Dr. Thompson for his guidance,
wisdom and support throughout the duration of this project. I
would also like to thank the entire York College Biology
Faculty Staff for any help or suggestions that they have
made with regards to this project.