The application of DOSY NMR and molecular dynamics simulations to explore the mechanism(s) of micelle binding of antimicrobial peptides containing unnatural amino acids

Biopolymers ◽  
2013 ◽  
Vol 99 (8) ◽  
pp. 548-561 ◽  
Author(s):  
Tiffany D. Clark ◽  
Libero Bartolotti ◽  
Rickey P. Hicks
2019 ◽  
Vol 24 (9) ◽  
pp. 928-938 ◽  
Author(s):  
Luca Palazzolo ◽  
Chiara Paravicini ◽  
Tommaso Laurenzi ◽  
Sara Adobati ◽  
Simona Saporiti ◽  
...  

SLC6A14 (ATB0,+) is a sodium- and chloride-dependent neutral and dibasic amino acid transporter that regulates the distribution of amino acids across cell membranes. The transporter is overexpressed in many human cancers characterized by an increased demand for amino acids; as such, it was recently acknowledged as a novel target for cancer therapy. The knowledge on the molecular mechanism of SLC6A14 transport is still limited, but some elegant studies on related transporters report the involvement of the 12 transmembrane α-helices in the transport mechanism, and describe structural rearrangements mediated by electrostatic interactions with some pivotal gating residues. In the present work, we constructed a SLC6A14 model in outward-facing conformation via homology modeling and used molecular dynamics simulations to predict amino acid residues critical for substrate recognition and translocation. We docked the proteinogenic amino acids and other known substrates in the SLC6A14 binding site to study both gating regions and the exposed residues involved in transport. Interestingly, some of these residues correspond to those previously identified in other LeuT-fold transporters; however, we could also identify a novel relevant residue with such function. For the first time, by combined approaches of molecular docking and molecular dynamics simulations, we highlight the potential role of these residues in neutral amino acid transport. This novel information unravels new aspects of the human SLC6A14 structure–function relationship and may have important outcomes for cancer treatment through the design of novel inhibitors of SLC6A14-mediated transport.


2018 ◽  
Vol 20 (40) ◽  
pp. 25901-25909 ◽  
Author(s):  
Rodrigo Ochoa ◽  
Miguel A. Soler ◽  
Alessandro Laio ◽  
Pilar Cossio

Single-point mutation protocols based on backbone-dependent rotamer libraries show the best performance in predicting equilibrium configurations from molecular dynamics simulations.


RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2047-2055 ◽  
Author(s):  
Eol Han ◽  
Hwankyu Lee

We performed coarse-grained molecular dynamics simulations of antimicrobial peptides PGLa and magainin 2 in lipid bilayers.


2021 ◽  
Author(s):  
Yevhen K. Cherniavskyi ◽  
Rosario Oliva ◽  
Marco Stellato ◽  
Pompea Del Vecchio ◽  
Stefania Galdiero ◽  
...  

Antimicrobial peptides are a promising class of alternative antibiotics that interact selectively with negatively charged lipid bilayers. This paper presents the structural characterization of the antimicrobial peptides myxinidin and WMR associated with bacterial membrane mimetic micelles and bicelles by NMR, CD spectroscopy, and Molecular Dynamics simulations. Both peptides adopt a different conformation in the lipidic environment than in aqueous solution. The location of peptides in micelles and bicelles has been studied by paramagnetic relaxation enhancement experiments with paramagnetic tagged 5- and 16-doxyl stearic acid (5-/16-SASL). Multi-microsecond long molecular dynamics simulations of multiple copies of the peptides were used to gain an atomic level of detail on membrane-peptide and peptide-peptide interactions. Our results highlight an essential role of the negatively charged membrane mimetic in the structural stability of both myxinidin and WMR. The peptides localize predominantly in the membrane's headgroup region and have a noticeable membrane thinning effect on the overall bilayer structure. Myxinidin and WMR show different tendency to self-aggregate, which is also influenced by the membrane composition (DOPE/DOPG versus DOPE/DOPG/CL) and can be related to the previously observed difference in the ability of the peptides to disrupt different types of model membranes.


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