How changes in the sequence of the peptide CLPFFD-NH2 can modify the conjugation and stability of gold nanoparticles and their affinity for beta-amyloid fibrils.
In a previous work, we studied the interaction of beta-amyloid fibrils (Abeta) with gold nanoparticles (AuNP) conjugated with the peptide CLPFFD-NH2. Here, we studied the effect of changing the residue sequence of the peptide CLPFFD-NH2 on the efficiency of conjugation to AuNP, the stability of the conjugates, and the affinity of the conjugates to the Abeta fibrils. We conjugated the AuNP with CLPFFD-NH 2 isomeric peptides (CDLPFF-NH2 and CLPDFF-NH2) and characterized the resulting conjugates with different techniques including UV-Vis, TEM, EELS, XPS, analysis of amino acids, agarose gel electrophoresis, and CD. In addition, we determined the proportion of AuNP bonded to the Abeta fibrils by ICP-MS. AuNP-CLPFFD-NH2 was the most stable of the conjugates and presented more affinity for Abeta fibrils with respect to the other conjugates and bare AuNP. These findings help to better understand the way peptide sequences affect conjugation and stability of AuNP and their interaction with Abeta fibrils. The peptide sequence, the steric effects, and the charge and disposition of hydrophilic and hydrophobic residues are crucial parameters when considering the design of AuNP peptide conjugates for biomedical applications.
Departamento de Química Farmacológica y Toxicológica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Olivos 1007, Chile.
Ivonne
I
Olmedo
Eyleen
E
Araya
Fausto
F
Sanz
Elias
E
Medina
Jordi
J
Arbiol
Pedro
P
Toledo
Alejandro
A
Alvarez-Lueje
Ernest
E
Giralt
Marcelo J
MJ
Kogan
D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D040761:Biomimetic Materials / Q000378:metabolism; D002942:Circular Dichroism; D019343:Citric Acid / Q000378:metabolism; D004583:Electrons; D006046:Gold / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D053768:Metal Nanoparticles / Q000737:chemistry*; D009842:Oligopeptides / Q000097:blood / Q000134:cerebrospinal fluid / Q000737:chemistry* / Q000378:metabolism*; D051381:Rats; D013499:Surface Properties
D016229:Amyloid beta-Peptides; D009842:Oligopeptides; D019343:Citric Acid; D006046:Gold