PMID- 29176615
OWN - NLM
STAT- In-Data-Review
LR  - 20171201
IS  - 2045-2322 (Electronic)
IS  - 2045-2322 (Linking)
VI  - 7
IP  - 1
DP  - 2017 Nov 24
TI  - Design and applications of a clamp for Green Fluorescent Protein with picomolar
      affinity.
PG  - 16292
LID - 10.1038/s41598-017-15711-z [doi]
AB  - Green fluorescent protein (GFP) fusions are pervasively used to study structures 
      and processes. Specific GFP-binders are thus of great utility for detection,
      immobilization or manipulation of GFP-fused molecules. We determined structures
      of two designed ankyrin repeat proteins (DARPins), complexed with GFP, which
      revealed different but overlapping epitopes. Here we show a structure-guided
      design strategy that, by truncation and computational reengineering, led to a
      stable construct where both can bind simultaneously: by linkage of the two
      binders, fusion constructs were obtained that "wrap around" GFP, have very high
      affinities of about 10-30 pM, and extremely slow off-rates. They can be natively 
      produced in E. coli in very large amounts, and show excellent biophysical
      properties. Their very high stability and affinity, facile site-directed
      functionalization at introduced unique lysines or cysteines facilitate many
      applications. As examples, we present them as tight yet reversible immobilization
      reagents for surface plasmon resonance, as fluorescently labelled monomeric
      detection reagents in flow cytometry, as pull-down ligands to selectively enrich 
      GFP fusion proteins from cell extracts, and as affinity column ligands for
      inexpensive large-scale protein purification. We have thus described a general
      design strategy to create a "clamp" from two different high-affinity repeat
      proteins, even if their epitopes overlap.
FAU - Hansen, Simon
AU  - Hansen S
AD  - Department of Biochemistry, University Zurich, Winterthurerstrasse 190, 8057,
      Zurich, Switzerland.
AD  - Department of Early Discovery Biochemistry, Genentech, 1 DNA Way, South San
      Francisco, California, 94080, USA.
FAU - Stuber, Jakob C
AU  - Stuber JC
AUID- ORCID: http://orcid.org/0000-0002-3406-0664
AD  - Department of Biochemistry, University Zurich, Winterthurerstrasse 190, 8057,
      Zurich, Switzerland.
FAU - Ernst, Patrick
AU  - Ernst P
AD  - Department of Biochemistry, University Zurich, Winterthurerstrasse 190, 8057,
      Zurich, Switzerland.
FAU - Koch, Alexander
AU  - Koch A
AD  - Department of Biochemistry, University Zurich, Winterthurerstrasse 190, 8057,
      Zurich, Switzerland.
FAU - Bojar, Daniel
AU  - Bojar D
AD  - Department of Biochemistry, University Zurich, Winterthurerstrasse 190, 8057,
      Zurich, Switzerland.
AD  - Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26,
      4058, Basel, Switzerland.
FAU - Batyuk, Alexander
AU  - Batyuk A
AUID- ORCID: http://orcid.org/0000-0002-9393-2880
AD  - Department of Biochemistry, University Zurich, Winterthurerstrasse 190, 8057,
      Zurich, Switzerland.
AD  - Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill
      Road, Menlo Park, California, 94025, USA.
FAU - Pluckthun, Andreas
AU  - Pluckthun A
AUID- ORCID: http://orcid.org/0000-0003-4191-5306
AD  - Department of Biochemistry, University Zurich, Winterthurerstrasse 190, 8057,
      Zurich, Switzerland. plueckthun@bioc.uzh.ch.
LA  - eng
PT  - Journal Article
DEP - 20171124
PL  - England
TA  - Sci Rep
JT  - Scientific reports
JID - 101563288
PMC - PMC5701241
EDAT- 2017/11/28 06:00
MHDA- 2017/11/28 06:00
CRDT- 2017/11/28 06:00
PHST- 2017/08/22 00:00 [received]
PHST- 2017/10/31 00:00 [accepted]
PHST- 2017/11/28 06:00 [entrez]
PHST- 2017/11/28 06:00 [pubmed]
PHST- 2017/11/28 06:00 [medline]
AID - 10.1038/s41598-017-15711-z [doi]
AID - 10.1038/s41598-017-15711-z [pii]
PST - epublish
SO  - Sci Rep. 2017 Nov 24;7(1):16292. doi: 10.1038/s41598-017-15711-z.