TY - JOUR
T1 - α-Lactalbumin nanoparticles prepared by desolvation and cross-linking
T2 - Structure and stability of the assembled protein
AU - Arroyo-Maya, Izlia J.
AU - Hernández-Sánchez, Humberto
AU - Jiménez-Cruz, Esmeralda
AU - Camarillo-Cadena, Menandro
AU - Hernández-Arana, Andrés
PY - 2014
Y1 - 2014
N2 - A key step in the preparation of cross-linked protein nanoparticles involves the desolvation of proteins with an organic solvent, which is thought to act by modulating hydrophobic interactions. However, to date, no study has examined the conformational changes that proteins undergo during the assembly process. In this work, by using several biophysical techniques (CD spectroscopy, DSC, TEM, etc.), we studied spheroidal nanoparticles made from bovine α-lactalbumin cross-linked with glutaraldehyde in the presence of acetone. Within the nanoparticle, the polypeptide chain acquires a β-strand-like conformation (completely different from the native protein in secondary and tertiary structure) in which several side chains likely become available for reacting with glutaraldehyde. A multiplicity of cross-linking sites, together with the polymeric nature of glutaraldehyde, may thus explain the low dry-weight fraction of protein that was found in the nanoparticles. Although covalent bonds undoubtedly constitute the main source for nanoparticle stability, noncovalent interactions also appear to play a role in this regard.
AB - A key step in the preparation of cross-linked protein nanoparticles involves the desolvation of proteins with an organic solvent, which is thought to act by modulating hydrophobic interactions. However, to date, no study has examined the conformational changes that proteins undergo during the assembly process. In this work, by using several biophysical techniques (CD spectroscopy, DSC, TEM, etc.), we studied spheroidal nanoparticles made from bovine α-lactalbumin cross-linked with glutaraldehyde in the presence of acetone. Within the nanoparticle, the polypeptide chain acquires a β-strand-like conformation (completely different from the native protein in secondary and tertiary structure) in which several side chains likely become available for reacting with glutaraldehyde. A multiplicity of cross-linking sites, together with the polymeric nature of glutaraldehyde, may thus explain the low dry-weight fraction of protein that was found in the nanoparticles. Although covalent bonds undoubtedly constitute the main source for nanoparticle stability, noncovalent interactions also appear to play a role in this regard.
KW - Circular dichroism
KW - Differential scanning calorimetry
KW - Nanoparticles
KW - Secondary structure
KW - α-Lactalbumin
UR - http://www.scopus.com/inward/record.url?scp=84905316361&partnerID=8YFLogxK
U2 - 10.1016/j.bpc.2014.07.003
DO - 10.1016/j.bpc.2014.07.003
M3 - Artículo
C2 - 25105879
SN - 0301-4622
VL - 193-194
SP - 27
EP - 34
JO - Biophysical Chemistry
JF - Biophysical Chemistry
ER -