Now showing items 1-3 of 3

Conserved binding regions provide the clue for peptide-based vaccine development: A chemical perspective

Curtidor, Hernando; Reyes, César; Bermúdez, Adriana; Vanegas, Magnolia; Varela, Yahson; Patarrollo, Manuel Elkin (2017)

Abstract: Synthetic peptides have become invaluable biomedical research and medicinal chemistry tools for studying functional roles, i.e., binding or proteolytic activity, naturally-occurring regions’ immunogenicity in ...
Easy and fast method for expression and native extraction of Plasmodium vivax Duffy binding protein fragments

Moreno Pérez, Darwin Andrés; Baquero, Luis Alfredo; Bermúdez, Maritza; Gómez Muñoz, Laura Alejandra; Varela, Yahson; Patarroyo, Manuel Alfonso (2018)

Background: The Plasmodium vivax Duffy binding protein (PvDBP) has been the most studied ligand binding human reticulocytes to date. This molecule has a cysteine-rich domain in region II (RII) which has been used as control ...
TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

Alba, Martha P.; Suarez, Carlos F.; Varela, Yahson; Patarroyo, Manuel A.; Bermudez, Adriana; Patarroyo, Manuel Elkin (2016)

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged ...

Envíos recientes

Conserved binding regions provide the clue for peptide-based vaccine development: A chemical perspective
...
Curtidor, Hernando | 2017

Abstract: Synthetic peptides have become invaluable biomedical research and medicinal chemistry tools for studying functional roles, i.e., binding or proteolytic activity, naturally-occurring regions’ immunogenicity in proteins and developing therapeutic agents and vaccines. Synthetic peptides can mimic protein sites; their structure and function can be easily modulated by specific amino acid replacement. They have major advantages, i.e., they are cheap, easily-produced and chemically stable, lack infectious and secondary adverse reactions and can induce immune responses via T- and B-cell epitopes. Our group has previously shown that using synthetic peptides and adopting a functional approach has led to identifying Plasmodium falciparum conserved regions binding to host cells. Conserved high activity binding peptides’ (cHABPs) physicochemical, structural and immunological characteristics have been taken into account for properly modifying and converting them into highly immunogenic, protection-inducing peptides (mHABPs) in the experimental Aotus monkey model. This article describes stereo–electron and topochemical characteristics regarding major histocompatibility complex (MHC)-mHABP-T-cell receptor (TCR) complex formation. Some mHABPs in this complex inducing long-lasting, protective immunity have been named immune protection-inducing protein structures (IMPIPS), forming the subunit components in chemically synthesized vaccines. This manuscript summarizes this particular field and adds our recent findings concerning intramolecular interactions (H-bonds or π-interactions) enabling proper IMPIPS structure as well as the peripheral flanking residues (PFR) to stabilize the MHCII-IMPIPS-TCR interaction, aimed at inducing long-lasting, protective immunological memory

LEER
Easy and fast method for expression and native extraction of Plasmodium vivax Duffy binding protein fragments
...
Moreno Pérez, Darwin Andrés | 2018

Background: The Plasmodium vivax Duffy binding protein (PvDBP) has been the most studied ligand binding human reticulocytes to date. This molecule has a cysteine-rich domain in region II (RII) which has been used as control for evaluating the target cell binding activity of several parasite molecules. However, obtaining rPvDBP-RII in a soluble form using the Escherichia coli expression system usually requires laborious and time-consuming steps for recovering the molecule's structure and function, considering it is extracted from inclusion bodies. The present study describes an easy and fast method for expressing and obtaining several PvDBP fragments which should prove ideal for use in protein-cell interaction assays. Results: Two PvDBP encoding regions (rii and riii/v) were cloned in pEXP5-CT vector and expressed in E. coli and extracted from the soluble fraction (rPvDBP-RIIS and rPvDBP-RIII/VS) using a simple freezing/thawing protocol. After the purification, dichroism analysis enabled verifying high rPvDBP-RIIS and rPvDBP-RIII/VS secondary structure α-helix content, which was lowered when molecules were extracted from inclusion bodies (rPvDBP-RIIIB and rPvDBP-RIII/VIB) using a denaturing step. Interestingly, rPvDBP-RIIS, but not rPvDBP-RIIIB, bound to human reticulocytes, while rPvDBP-RIII/VS and rPvDBP-RIII/VIB bound to such cells in a similar way to negative control (cells incubated without recombinant proteins). Conclusions: This research has shown for the first time how rPvDBP-RII can be expressed and obtained in soluble form using the E. coli system and avoiding the denaturation and refolding steps commonly used. The results highlight the usefulness of the rPvDBP-RIII/VS fragment as a non-binding control for protein-cell target interaction assays. The soluble extraction protocol described is a good alternative to obtain fully functional P. vivax proteins in a fast and easy way, which will surely prove useful to laboratories working in studying this parasite's biology.

LEER
TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria
...
Alba, Martha P. | 2016

Fully-protective, long-lasting, immunological (FPLLI) memory against Plasmodium falciparum malaria regarding immune protection-inducing protein structures (IMPIPS) vaccinated into monkeys previously challenged and re-challenged 60 days later with a lethal Aotus monkey-adapted P. falciparum strain was found to be associated with preferential high binding capacity to HLA-DRβ1* allelic molecules of the major histocompatibility class II (MHC-II), rather than HLA-DRβ3*, β4*, β5* alleles. Complete PPIIL 3D structure, a longer distance (26.5 Å ± 1.5 Å) between residues perfectly fitting into HLA-DRβ1*PBR pockets 1 and 9, a gauche− rotamer orientation in p8 TCR-contacting polar residue and a larger volume of polar p2 residues was also found. This data, in association with previously-described p3 and p7 apolar residues having gauche+ orientation to form a perfect MHC-II-peptide-TCR complex, determines the stereo-electronic and topochemical characteristics associated with FPLLI immunological memory.

LEER

‹›

Browsing by Author "Varela, Yahson"

Conserved binding regions provide the clue for peptide-based vaccine development: A chemical perspective ﻿

Easy and fast method for expression and native extraction of Plasmodium vivax Duffy binding protein fragments ﻿

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria ﻿

Envíos recientes

Conserved binding regions provide the clue for peptide-based vaccine development: A chemical perspective

Easy and fast method for expression and native extraction of Plasmodium vivax Duffy binding protein fragments

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria

Conserved binding regions provide the clue for peptide-based vaccine development: A chemical perspective

Easy and fast method for expression and native extraction of Plasmodium vivax Duffy binding protein fragments

TCR-contacting residues orientation and HLA-DRβ* binding preference determine long-lasting protective immunity against malaria