Structure–Activity Studies of β-Hairpin Peptide Inhibitors of the Plasmodium falciparum AMA1–RON2 Interaction

Wang, Geqing; Drinkwater, N.; Drew, Damien R.; MacRaild, Christopher A.; Chalmers, David K.; Mohanty, Biswaranjan; Lim, San Sui; Anders, Robin F.; Beeson, James G.; Thompson, Phillip E.; McGowan, Sheena; Simpson, Jamie S.; Norton, Raymond S.; Scanlon, M.J.

doi:10.1016/j.jmb.2016.07.001

Cited by 23 publications

(38 citation statements)

References 42 publications

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“…As for native RON2hp, the peptides retained as light preference for binding to FVO PfAMA1 over 3D7 PfAMA1 owing to an additional interaction with the polymorphicA sn225 residue. [31] The Cys2037-d-Pro2049 linked peptide bound to FVO PfAMA1 with an affinity of 7 mm,w hereas d-Pro2037-Cys2049s howed much weaker binding (Table1). A9 -fold decrease in affinity for FVO PfAMA1 from the parent peptide might arise from changes in local geometry around the disulfide bond.…”

Section: Design and Development Of The Probementioning

confidence: 98%

“…The spin-labelled probe wasd esigned based on the truncated 13-residue disulfide-bridged b-hairpin corresponding to the C-terminal loop of RON2,R ON2hp[F2038W,Q2046M] (CWTTRMSPPMQIC) (Figure1A). [31] Unlike the longerR ON2sp1 peptide, RON2hp leaves most of the hydrophobic cleft free. The disulfide-bridge is positioned towardt he centre of the hydrophobic cleft that has been identified as the primaryh ot spot for small-molecule binding, [32] and thus offers an ideal site for Cys specific spin-labellingt oc onfer PRE effects on molecules bound to the cleft.…”

Section: Design and Development Of The Probementioning

confidence: 99%

“…This indicates that the peptidem ight adopt multiple conformationsi n solution, similar to the parent peptide. [31] For the spin-labelled peptide, the free thiol group of Cys2037 of bcRON2hp specificallyr eactedw ith the thiosulfonate ester group of the MTSL spin label at neutral pH, with a final product yield of > 95 %a nd 100 %p urity (SI Figure S1 C). The 1D 1 Hs pectrumo ft he spin-labelled peptide, N*bcRON2hp was characterised by extensive line broadening,w ith the most obvious effects on the Trp2038 indolep eak adjacent to the MTSL-labelled Cys2037 (SI Figure S1 D).…”

Section: Design and Development Of The Probementioning

confidence: 99%

“…[24,[26][27][28] In fragment-based ligand design,aligand with a defined binding site can be spin-labelled to searchf or second ligandst hat bind to adjacent sites. [25,29,30] Adopting this concept of second-site screening, here we describe the design, synthesis and application of as pin-labelled probe based on the C-terminall oop of the RON2 peptide [31] that would bind to the hydrophobic clefto fA MA1 and exert PRE effects on ligands bound nearby.O ur designed peptidew as based on a 13-residue truncated, disulfide-cyclised b-hairpin of RON2, RON2hp (CWTTRMSPPMQIC), [31] which, unlike longerR ON2 peptides RON2sp1 or RON2sp2, makes extensive contacts with only one end of the hydrophobic cleft and leaves most of the cleft exposed. The disulfide bridge of RON2hp faces toward the centre of the hydrophobic cleft that has been identified as the primary hot spot for small-molecule binding.…”

Section: Introductionmentioning

confidence: 99%

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Identification of the Binding Site of Apical Membrane Antigen 1 (AMA1) Inhibitors Using a Paramagnetic Probe

et al. 2019

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Apical membrane antigen 1 (AMA1) is essential for the invasion of host cells by malaria parasites. Several small‐molecule ligands have been shown to bind to a conserved hydrophobic cleft in Plasmodium falciparum AMA1. However, a lack of detailed structural information on the binding pose of these molecules has hindered their further optimisation as inhibitors. We have developed a spin‐labelled peptide based on RON2, the native binding partner of AMA1, to probe the binding sites of compounds on PfAMA1. The crystal structure of this peptide bound to PfAMA1 shows that it binds at one end of the hydrophobic groove, leaving much of the binding site unoccupied and allowing fragment hits to bind without interference. In paramagnetic relaxation enhancement (PRE)‐based NMR screening, the 1H relaxation rates of compounds binding close to the probe were enhanced. Compounds experienced different degrees of PRE as a result of their different orientations relative to the spin label while bound to AMA1. Thus, PRE‐derived distance constraints can be used to identify binding sites and guide further hit optimisation.

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Section: Design and Development Of The Probementioning

confidence: 98%

Section: Design and Development Of The Probementioning

confidence: 99%

Section: Design and Development Of The Probementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Identification of the Binding Site of Apical Membrane Antigen 1 (AMA1) Inhibitors Using a Paramagnetic Probe

et al. 2019

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“…During this process, the connection between the two cells is maintained by the interaction between Pf AMA1 located on the surface of the parasite and Pf Ron2, another P. falciparum protein, which is translocated to the erythrocyte membrane early in the process (23–25). Previous studies have shown that antibodies (26–28), peptides (29, 30), and drugs (31, 32) that interfere with the AMA1–Ron2 interaction in different plasmodium species inhibit the growth of the parasite. Additionally, structural analysis of the Pf AMA1– Pf Ron2 complex has revealed extensive conformational changes in the Pf AMA1 variable loops surrounding the Pf Ron2-binding pocket compared to Pf AMA1 alone (25, 33–35) making those regions particularly interesting as targets for potent parasite growth-inhibitory antibodies.…”

Section: Introductionmentioning

confidence: 99%

Immunization with the Malaria Diversity-Covering Blood-Stage Vaccine Candidate Plasmodium falciparum Apical Membrane Antigen 1 DiCo in Complex with Its Natural Ligand PfRon2 Does Not Improve the In Vitro Efficacy

et al. 2017

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The blood-stage malaria vaccine candidate Plasmodium falciparum apical membrane antigen 1 (PfAMA1) can induce strong parasite growth-inhibitory antibody responses in animals but has not achieved the anticipated efficacy in clinical trials. Possible explanations in humans are the insufficient potency of the elicited antibody responses, as well as the high degree of sequence polymorphisms found in the field. Several strategies have been developed to improve the cross-strain coverage of PfAMA1-based vaccines, whereas innovative concepts to increase the potency of PfAMA1-specific IgG responses have received little attention even though this may be an essential requirement for protective efficacy. A previous study has demonstrated that immunization with a complex of PyAMA1 and PyRON2, a ligand with an essential functional role in erythrocyte invasion, leads to protection from lethal Plasmodium yoelli challenge in an animal model and suggested to extend this strategy toward improved strain coverage by using multiple PfAMA1 alleles in combination with PfRon2L. As an alternative approach along this line, we decided to use PfRon2L in combination with three PfAMA1 diversity covering variants (DiCo) to investigate the potential of this complex to induce more potent parasite growth inhibitory immune response in combination with better cross-strain-specific efficacy. Within the limits of the study design, the ability of the PfAMA1 DiCo-Mix to induce cross-strain-specific antibodies was not affected in all immunization groups, but the DiCo–PfRon2L complexes did not improve the potency of PfAMA1-specific IgG responses.

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A Chimeric Peptide Inhibits Red Blood Cell Invasion by Plasmodium falciparum with Hundredfold Increased Efficacy**

et al. 2022

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Dedicated to Professor Sambasivarao Kotha on the occasion of his 65th birthday.Inhibiting the formation of a tight junction between two malaria parasite proteins, apical membrane antigen 1 and rhoptry neck protein 2, crucial for red blood cell invasion, prevents progression of the disease. In this work, we have used a unique approach to design a chimeric peptide, prepared by fusion of the best features of two peptide inhibitors, that has displayed parasite growth inhibition ex vivo with nanomolar IC 50 , which is 100 times better than any of its parent peptides. Furthermore, to gain structural insights, we computationally modelled the hybrid peptide on its receptor. 2055 (PDB ID: 3SRI) and performed short molecular dynamics (MD) simulations (two repeats of 30 ns). As two molecules of R1[a] Dr. J.

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Structure–Activity Studies of β-Hairpin Peptide Inhibitors of the Plasmodium falciparum AMA1–RON2 Interaction

Cited by 23 publications

References 42 publications

Identification of the Binding Site of Apical Membrane Antigen 1 (AMA1) Inhibitors Using a Paramagnetic Probe

Identification of the Binding Site of Apical Membrane Antigen 1 (AMA1) Inhibitors Using a Paramagnetic Probe

Immunization with the Malaria Diversity-Covering Blood-Stage Vaccine Candidate Plasmodium falciparum Apical Membrane Antigen 1 DiCo in Complex with Its Natural Ligand PfRon2 Does Not Improve the In Vitro Efficacy

A Chimeric Peptide Inhibits Red Blood Cell Invasion by Plasmodium falciparum with Hundredfold Increased Efficacy**

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