Luo MB, Ziebarth JD, Wang Y. Interplay of Coil-Globule Transition and Surface Adsorption of a Lattice HP Protein Model.
J Phys Chem B 2014;
118:14913-21. [PMID:
25458556 PMCID:
PMC4280116 DOI:
10.1021/jp506126d]
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Abstract
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An
end-grafted hydrophobic-polar (HP) model protein chain with
alternating H and P monomers is studied to examine interactions between
the critical adsorption transition due to surface attraction and the
collapse transition due to pairwise attractive H–H interactions.
We find that the critical adsorption phenomenon can always be observed;
however, the critical adsorption temperature TCAP is influenced by the attractive H–H interactions
in some cases. When the collapse temperature Tc is lower than TCAP, the critical
adsorption of the HP chain is similar to that of a homopolymer without
intrachain attractions and TCAP remains
unchanged, whereas the collapse transition is suppressed by the adsorption.
In contrast, for cases where Tc is close
to or higher than TCAP, TCAP of the HP chain is increased, indicating that a collapsed
chain is more easily adsorbed on the surface. The strength of the
H–H attraction also influences the statistical size and shape
of the polymer, with strong H–H attractions resulting in adsorbed
and collapsed chains adopting two-dimensional, circular conformations.
Collapse