Structure and functional dynamics characterization of the ion channel of the human respiratory syncytial virus (hRSV) small hydrophobic protein (SH) transmembrane domain by combining molecular dynamics with excited normal modes.
The human respiratory syncytial virus (hRSV) is the major cause of lower respiratory tract infection in children and elderly people worldwide. Its genome encodes 11 proteins including SH protein, whose functions are not well known. Studies show that SH protein increases RSV virulence degree and permeability to small compounds, suggesting it is involved in the formation of ion channels. The knowledge of SH structure and function is fundamental for a better understanding of its infection mechanism. The aim of this study was to model, characterize, and analyze the structural behavior of SH protein in the phospholipids bilayer environment. Molecular modeling of SH pentameric structure was performed, followed by traditional molecular dynamics (MD) simulations of the protein immersed in the lipid bilayer. Molecular dynamics with excited normal modes (MDeNM) was applied in the resulting system in order to investigate long time scale pore dynamics. MD simulations support that SH protein is stable in its pentameric form. Simulations also showed the presence of water molecules within the bilayer by density distribution, thus confirming that SH protein is a viroporin. This water transport was also observed in MDeNM studies with histidine residues of five chains (His22 and His51), playing a key role in pore permeability. The combination of traditional MD and MDeNM was a very efficient protocol to investigate functional conformational changes of transmembrane proteins that act as molecular channels. This protocol can support future investigations of drug candidates by acting on SH protein to inhibit viral infection. Graphical Abstract The ion channel of the human respiratory syncytial virus (hRSV) small hydrophobic protein (SH) transmembrane domainᅟ.
Laboratório Multiusuário de Inovação Biomolecular, Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil.
Gabriela C
GC
Araujo
Laboratório de Biologia Computacional e Bioinformática, Universidade Federal do ABC, Santo André, SP, Brazil.
Ricardo H T
RH
Silva
Laboratório de Biologia Computacional e Bioinformática, Universidade Federal do ABC, Santo André, SP, Brazil.
Luis P B
LP
Scott
Laboratório Multiusuário de Inovação Biomolecular, Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil.
Alexandre S
AS
Araujo
Laboratório Multiusuário de Inovação Biomolecular, Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, SP, Brazil. fatyssouza@gmail.com.
Fatima P
FP
Souza
Laboratório de Física Teórica, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação, Universidade Federal do Triângulo Mineiro, Uberaba, MG, Brazil.
Ronaldo Junio
RJ
de Oliveira
D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007473:Ion Channels / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism
D007473:Ion Channels; D008565:Membrane Proteins; D014764:Viral Proteins
Excited normal modes; Molecular dynamics; RSV; SH protein; Viroporin