Specific cellular labeling of nuclear and membrane proteins with antibody alternatives: Affimer and nanobody

Ren, Pin

Permalink

https://hdl.handle.net/2142/113981 Copy

Description

Title

Specific cellular labeling of nuclear and membrane proteins with antibody alternatives: Affimer and nanobody

Author(s)

Ren, Pin

Issue Date

2021-11-30

Director of Research (if dissertation) or Advisor (if thesis)

Selvin, Paul

Doctoral Committee Chair(s)

Selvin, Paul

Committee Member(s)

• Chemla, Yann
• Luthey-Schulten, Zaida Ann
• Nelson, Erik

Department of Study

School of Molecular & Cell Bio

Discipline

Biophysics & Quant Biology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Antibody Alternatives
• Fluoresecence Microscopy
• Live Cell Imaging

Abstract

Antibodies have proven to be useful tools in fluorescence imaging to identify targets in cells. In large part, this is because they have specific immunoreactivity to their targets. However, they also have serious problems: cross-reactivity with non-target proteins, poor cell permeability, batch-to-batch variability, complicated production procedures, and large size (~150 kD) that makes them impermeant to the cell membrane and require onerous efforts for live cell labeling. Hence, we explore alternative binding proteins. We chose three antibody-like proteins which are all small (< 15 kD), yet have very high affinity and specificity to their targets and, if necessary, can be easily driven through the cell and nuclear membrane. For internal labeling, we use an Affimer to detect the Y537S mutant of the Estrogen Receptor alpha, and a nanobody to detect tumor suppressor protein p53, two important proteins involved in cancer. We also use a commercially available nanobody, called Spot nanobody, to detect the AMPAR and N-methyl-D-aspartate receptor (NMDAR), two important cell membrane-bound receptor proteins in the neuron synapse. In all cases, we conjugate these antibody-like proteins with organic fluorophores and deliver them into live cells by transiently permeabilizing the cells with Streptolysin O (SLO). Single molecule sensitivity is shown for each of them and important biological results are presented.

Graduation Semester

2021-12

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/113981

Copyright and License Information

Copyright 2021 Pin Ren

Owning Collections