Based on a newly developed contact-density chain-growth algorithm, we have
simulated a nongrafted peptide in the vicinity of different attractive
substrates. We analyzed the specificity of the peptide adsorption by focussing
on the conformational transitions the peptide experiences in the
binding/unbinding processes. In a single simulation run, we obtained the
contact density, i.e., the distribution of intrinsic monomer-monomer contacts
and monomer-substrate nearest-neighbor contacts. This allows a systematic
reweighting to all values of external control parameters such as temperature
and solvent quality after the simulation. The main result is the complete
solubility-temperature pseudo-phase diagram which is based on the corresponding
specific-heat profile. We find a surprisingly rich structure of pseudo-phases
that can roughly be classified into compact and expanded conformations in both
regimes, adsorption and desorption. Furthermore, underlying subphases were
identified, which, in particular, appear noticeably in the compact
pseudo-phases.Comment: 8 pages, 3 figure