Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample

Shifeng Guo, Xiaoying Zhu, Dominik Jańczewski (Corresponding Author), Serina Siew Chen Lee, Tao He, Serena Lay Ming Teo, G. Julius Vancso (Corresponding Author)

Research output: Contribution to journalArticleAcademicpeer-review

16 Citations (Scopus)
1 Downloads (Pure)

Abstract

Protein charge at various pH and isoelectric point (pI) values is important in understanding protein function. However, often only trace amounts of unknown proteins are available and pI measurements cannot be obtained using conventional methods. Here, we show a method based on the atomic force microscope (AFM) to determine pI using minute quantities of proteins. The protein of interest is immobilized on AFM colloidal probes and the adhesion force of the protein is measured against a positively and a negatively charged substrate made by layer-by-layer deposition of polyelectrolytes. From the AFM force–distance curves, pI values with an estimated accuracy of ±0.25 were obtained for bovine serum albumin, myoglobin, fibrinogen and ribonuclease A over a range of 4.7–9.8. Using this method, we show that the pI of the ‘footprint’ of the temporary adhesive proteins secreted by the barnacle cyprid larvae of Amphibalanus amphitrite is in the range 9.6–9.7.
Original languageEnglish
Pages (from-to)817-823
JournalNature nanotechnology
Volume11
DOIs
Publication statusPublished - 2016

Fingerprint

Microscopes
microscopes
Spectroscopy
proteins
Proteins
spectroscopy
larvae
fibrinogen
Pancreatic Ribonuclease
myoglobin
Myoglobin
footprints
Bovine Serum Albumin
Polyelectrolytes
albumins
serums
Fibrinogen
adhesives
Adhesives
adhesion

Keywords

  • METIS-318036
  • IR-101770

Cite this

Guo, Shifeng ; Zhu, Xiaoying ; Jańczewski, Dominik ; Lee, Serina Siew Chen ; He, Tao ; Teo, Serena Lay Ming ; Vancso, G. Julius. / Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample. In: Nature nanotechnology. 2016 ; Vol. 11. pp. 817-823.
@article{2eaadcb419a34c438634221fd49df90e,
title = "Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample",
abstract = "Protein charge at various pH and isoelectric point (pI) values is important in understanding protein function. However, often only trace amounts of unknown proteins are available and pI measurements cannot be obtained using conventional methods. Here, we show a method based on the atomic force microscope (AFM) to determine pI using minute quantities of proteins. The protein of interest is immobilized on AFM colloidal probes and the adhesion force of the protein is measured against a positively and a negatively charged substrate made by layer-by-layer deposition of polyelectrolytes. From the AFM force–distance curves, pI values with an estimated accuracy of ±0.25 were obtained for bovine serum albumin, myoglobin, fibrinogen and ribonuclease A over a range of 4.7–9.8. Using this method, we show that the pI of the ‘footprint’ of the temporary adhesive proteins secreted by the barnacle cyprid larvae of Amphibalanus amphitrite is in the range 9.6–9.7.",
keywords = "METIS-318036, IR-101770",
author = "Shifeng Guo and Xiaoying Zhu and Dominik Jańczewski and Lee, {Serina Siew Chen} and Tao He and Teo, {Serena Lay Ming} and Vancso, {G. Julius}",
year = "2016",
doi = "10.1038/nnano.2016.118",
language = "English",
volume = "11",
pages = "817--823",
journal = "Nature nanotechnology",
issn = "1748-3387",
publisher = "Nature Publishing Group",

}

Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample. / Guo, Shifeng; Zhu, Xiaoying; Jańczewski, Dominik (Corresponding Author); Lee, Serina Siew Chen; He, Tao; Teo, Serena Lay Ming; Vancso, G. Julius (Corresponding Author).

In: Nature nanotechnology, Vol. 11, 2016, p. 817-823.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample

AU - Guo, Shifeng

AU - Zhu, Xiaoying

AU - Jańczewski, Dominik

AU - Lee, Serina Siew Chen

AU - He, Tao

AU - Teo, Serena Lay Ming

AU - Vancso, G. Julius

PY - 2016

Y1 - 2016

N2 - Protein charge at various pH and isoelectric point (pI) values is important in understanding protein function. However, often only trace amounts of unknown proteins are available and pI measurements cannot be obtained using conventional methods. Here, we show a method based on the atomic force microscope (AFM) to determine pI using minute quantities of proteins. The protein of interest is immobilized on AFM colloidal probes and the adhesion force of the protein is measured against a positively and a negatively charged substrate made by layer-by-layer deposition of polyelectrolytes. From the AFM force–distance curves, pI values with an estimated accuracy of ±0.25 were obtained for bovine serum albumin, myoglobin, fibrinogen and ribonuclease A over a range of 4.7–9.8. Using this method, we show that the pI of the ‘footprint’ of the temporary adhesive proteins secreted by the barnacle cyprid larvae of Amphibalanus amphitrite is in the range 9.6–9.7.

AB - Protein charge at various pH and isoelectric point (pI) values is important in understanding protein function. However, often only trace amounts of unknown proteins are available and pI measurements cannot be obtained using conventional methods. Here, we show a method based on the atomic force microscope (AFM) to determine pI using minute quantities of proteins. The protein of interest is immobilized on AFM colloidal probes and the adhesion force of the protein is measured against a positively and a negatively charged substrate made by layer-by-layer deposition of polyelectrolytes. From the AFM force–distance curves, pI values with an estimated accuracy of ±0.25 were obtained for bovine serum albumin, myoglobin, fibrinogen and ribonuclease A over a range of 4.7–9.8. Using this method, we show that the pI of the ‘footprint’ of the temporary adhesive proteins secreted by the barnacle cyprid larvae of Amphibalanus amphitrite is in the range 9.6–9.7.

KW - METIS-318036

KW - IR-101770

U2 - 10.1038/nnano.2016.118

DO - 10.1038/nnano.2016.118

M3 - Article

VL - 11

SP - 817

EP - 823

JO - Nature nanotechnology

JF - Nature nanotechnology

SN - 1748-3387

ER -