The image illustrates how proteins (copper-colored coils) modified with polyhistidine-tags (green diamonds) can be attached to nanoparticles (red circle). Credit: SUNY University at Buffalo, Jonathan Lovell.
Fastening protein-based medical treatments to nanoparticles isn’t easy. With arduous chemistry, scientists can do it. But the fragile binding that holds them together often separates. This problem, which has limited how doctors can use proteins to treat serious disease, may soon change. University at Buffalo researchers have discovered a way to easily and effectively fasten proteins to nanoparticles – essentially an arranged marriage – by simply mixing them together. While in its infancy, the biotechnology model already has shown promise for developing an HIV vaccine and as a way to target cancer cells.
To create the biotechnology, the researchers use nanoparticles made of chlorophyll (a natural pigment), phospholipid (a fat similar to vegetable oil) and cobalt (a metal often used to prepare magnetic, water-resistant and high-strength alloys). The proteins, meanwhile, are modified with a chain of amino acids called a polyhistidine-tag. Uncommon in medicine, polyhistidine-tags are used extensively in protein research. Next, the researchers mixed the modified proteins and nanoparticles in water. There, one end of the protein embeds into the nanoparticle’s outer layer while the rest of it sticks out like a tentacle. To test the new binding model’s usefulness, the researchers added to it an adjuvant, which is an immunological agent used to enhance the efficacy of vaccines and drug treatments. The results were impressive. The three parts – adjuvant, protein and nanoparticle – worked together to stimulate an immune response against HIV.