Abstract
The surface force apparatus was used to measure directly the molecular forces between streptavidin and lipid bilayers displaying grafted M(r) 2,000 poly(ethylene glycol) (PEG). These measurements provide direct evidence for the formation of relatively strong attractive forces between PEG and protein. At low compressive loads, the forces were repulsive, but they became attractive when the proteins were pressed into the polymer layer at higher loads. The adhesion was sufficiently robust that separation of the streptavidin and PEG uprooted anchored polymer from the supporting membrane. These interactions altered the properties of the grafted chains. After the onset of the attraction, the polymer continued to bind protein for several hours. The changes were not due to protein denaturation. These data demonstrate directly that the biological activity of PEG is not due solely to properties of simple polymers such as the excluded volume. It is also coupled to the competitive interactions between solvent and other materials such as proteins for the chain segments and to the ability of this material to adopt higher order intrachain structures.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 8399-8404 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 94 |
| Issue number | 16 |
| DOIs | |
| State | Published - Aug 5 1997 |
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Measurements of attractive forces between proteins and end-grafted poly(ethylene glycol) chains. / Sheth, S. R.; Leckband, Deborah E.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 94, No. 16, 05.08.1997, p. 8399-8404.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Measurements of attractive forces between proteins and end-grafted poly(ethylene glycol) chains
AU - Sheth, S. R.
AU - Leckband, Deborah E
PY - 1997/8/5
Y1 - 1997/8/5
N2 - The surface force apparatus was used to measure directly the molecular forces between streptavidin and lipid bilayers displaying grafted M(r) 2,000 poly(ethylene glycol) (PEG). These measurements provide direct evidence for the formation of relatively strong attractive forces between PEG and protein. At low compressive loads, the forces were repulsive, but they became attractive when the proteins were pressed into the polymer layer at higher loads. The adhesion was sufficiently robust that separation of the streptavidin and PEG uprooted anchored polymer from the supporting membrane. These interactions altered the properties of the grafted chains. After the onset of the attraction, the polymer continued to bind protein for several hours. The changes were not due to protein denaturation. These data demonstrate directly that the biological activity of PEG is not due solely to properties of simple polymers such as the excluded volume. It is also coupled to the competitive interactions between solvent and other materials such as proteins for the chain segments and to the ability of this material to adopt higher order intrachain structures.
AB - The surface force apparatus was used to measure directly the molecular forces between streptavidin and lipid bilayers displaying grafted M(r) 2,000 poly(ethylene glycol) (PEG). These measurements provide direct evidence for the formation of relatively strong attractive forces between PEG and protein. At low compressive loads, the forces were repulsive, but they became attractive when the proteins were pressed into the polymer layer at higher loads. The adhesion was sufficiently robust that separation of the streptavidin and PEG uprooted anchored polymer from the supporting membrane. These interactions altered the properties of the grafted chains. After the onset of the attraction, the polymer continued to bind protein for several hours. The changes were not due to protein denaturation. These data demonstrate directly that the biological activity of PEG is not due solely to properties of simple polymers such as the excluded volume. It is also coupled to the competitive interactions between solvent and other materials such as proteins for the chain segments and to the ability of this material to adopt higher order intrachain structures.
UR - http://www.scopus.com/inward/record.url?scp=0030831255&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030831255&partnerID=8YFLogxK
U2 - 10.1073/pnas.94.16.8399
DO - 10.1073/pnas.94.16.8399
M3 - Article
C2 - 9237988
AN - SCOPUS:0030831255
VL - 94
SP - 8399
EP - 8404
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 16
ER -