New protein purification method could make protein drugs cheaper

Good news! Impressive!

"One of the most expensive steps in manufacturing protein drugs such as antibodies or insulin is the purification step: isolating the protein from the bioreactor used to produce it. This step can account for up to half of the total cost of manufacturing a protein. ...
“This work uses bioconjugate-functionalized nanoparticles to act as templates for enhancing protein crystal formation at low concentrations,” ...
The researchers demonstrated that their approach can be used to crystallize lysozyme (an antimicrobial enzyme) and insulin. They believe it could also be applied to many other useful proteins, including antibody drugs and vaccines. ...
To create the surface they needed, the researchers coated gold nanoparticles with molecules called bioconjugates — materials that can help form links between other molecules. For this study, the researchers used bioconjugates called maleimide and NHS, which are commonly used for tagging proteins for study or attaching protein drugs to drug-delivering nanoparticles. ...
When solutions of proteins are exposed to these coated nanoparticles, the proteins accumulate at the surface and bind to the bioconjugates. Furthermore, the bioconjugates compel the proteins to align themselves with a specific orientation, creating a scaffold for additional proteins to come along and join the crystal. ..."

From the abstract:

"Although protein crystallization offers a promising alternative to chromatography for lower-cost protein purification, slow nucleation kinetics and high protein concentration requirements are major barriers for using crystallization as a viable strategy in downstream protein purification. Here, we demonstrate that nanoparticles functionalized with bioconjugates can result in an in situ template for inducing rapid crystallization of proteins at low protein concentration conditions. We use a microbatch crystallization setup to show that the range of successful crystallization conditions is expanded by the presence of functionalized nanoparticles. Furthermore, we use a custom machine learning-enabled emulsion crystallization setup to rigorously quantify nucleation parameters. We show that bioconjugate-functionalized nanoparticles can result in up to a 7-fold decrease in the induction time and a 3-fold increase in the nucleation rate of model proteins compared to those in control environments. We thus provide foundational insight that could enable crystallization to be used in protein manufacturing by reducing both the protein concentration and the time required to nucleate protein crystals."

New purification method could make protein drugs cheaper | MIT News | Massachusetts Institute of Technology MIT engineers find specialized nanoparticles can quickly and inexpensively isolate proteins from a bioreactor.

Enhancing Protein Crystal Nucleation Using In Situ Templating on Bioconjugate-Functionalized Nanoparticles and Machine Learning (open access)

A microfluidic device was designed to combine protein solution with nanoparticles and then form thousands of tiny, identical droplets. Inside each of these droplets, the proteins interact with the nanoparticles, which help them to form protein crystals.

Figure 1. (a) Schematic illustrating the concept of nanoparticle-assisted nucleation. (b) Conjugation of proteins to gold nanoparticles via the target amino acids. (c) Optical images of representative crystals obtained from vapor diffusion experiments with different nanoparticles.