Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sensitivity of Water Dynamics to Biologically Significant Surfaces of
  Monomeric Insulin: Role of Topology and Electrostatic Interactions   In addition to the biologically active monomer of the protein Insulin
circulating in human blood, the molecule also exists in dimeric and hexameric
forms that are used as storage. The Insulin monomer contains two distinct
surfaces, namely the dimer forming surface (DFS) and the hexamer forming
surface (HFS) that are specifically designed to facilitate the formation of the
dimer and the hexamer, respectively. In order to characterize the structural
and dynamical behaviour of interfacial water molecules near these two surfaces
(DFS and HFS), we performed atomistic molecular dynamics simulations of Insulin
with explicit water. Dynamical characterization reveals that the structural
relaxation of the hydrogen bonds formed between the residues of DFS and the
interfacial water molecules is faster than those formed between water and that
of the HFS. Furthermore, the residence times of water molecules in the protein
hydration layer for both the DFS and HFS are found to be significantly higher
than those for some of the other proteins studied so far, such as HP-36 and
lysozyme. The surface topography and the arrangement of amino acid residues
work together to organize the water molecules in the hydration layer in order
to provide them with a preferred orientation. HFS having a large polar solvent
accessible surface area and a convex extensive nonpolar region, drives the
surrounding water molecules to acquire predominantly a clathrate-like
structure. In contrast, near the DFS, the surrounding water molecules acquire
an inverted orientation owing to the flat curvature of hydrophobic surface and
interrupted hydrophilic residual alignment. We have followed escape trajectory
of several such quasi-bound water molecules from both the surfaces and
constructed free energy surfaces of these water molecules.These free energy
surfaces reveal the differences between the two hydration layers.

12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph