alpha-Lactalbumin nanoparticles prepared by desolvation and cross-linking: Structure and stability of the assembled protein

作者：Arroyo Maya Izlia J^*; Hernandez Sanchez Humberto; Jimenez Cruz Esmeralda; Camarillo Cadena Menandro; Hernandez Arana Andres

来源：Biophysical Chemistry, 2014, 193: 27-34.

DOI：10.1016/j.bpc.2014.07.003

• alpha-Lactalbumin
• Nanoparticles
• Secondary structure
• Circular dichroism
• Differential scanning calorimetry

A key step in the preparation of cross-linked protein nanoparticles involves the desolvadon 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 alpha-lactalbumin cross-linked with glutaraldehyde in the presence of acetone. Within the nanoparticle, the polypeptide chain acquires a beta-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.

• 出版日期2014-10