A Crowding Barrier to Protein Inhibition in Colloidal Aggregates
| Autor: | Brian K. Shoichet, Henry R. O’Donnell, Xuewen Du, Matthew P. Jacobson, P. Lak |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
endocrine system
Medicinal & Biomolecular Chemistry Plasma protein binding 01 natural sciences complex mixtures beta-Lactamases Article Incubation period Chemical kinetics 03 medical and health sciences Colloid Medicinal and Biomolecular Chemistry Adsorption Bacterial Proteins Malate Dehydrogenase Drug Discovery Colloids Incubation Fulvestrant 030304 developmental biology Enzyme Assays 0303 health sciences Chemistry Organic Chemistry digestive oral and skin physiology Pharmacology and Pharmaceutical Sciences Sorafenib Small molecule 0104 chemical sciences 010404 medicinal & biomolecular chemistry Kinetics Drug delivery Biophysics Molecular Medicine Protein Binding |
| Zdroj: | J Med Chem Journal of medicinal chemistry, vol 64, iss 7 |
| ISSN: | 1520-4804 |
| Popis: | Small molecule colloidal aggregates adsorb and partially denature proteins, inhibiting them artifactually. Oddly, this inhibition is typically time-dependent. Two mechanisms might explain this: low concentrations of the colloid and enzyme might mean low encounter rates, or colloid-based protein denaturation might impose a kinetic barrier. These two mechanisms should have different concentration dependencies. Perplexingly, when enzyme concentration was increased, incubation times actually lengthened, inconsistent with both models and with classical chemical kinetics of solution species. We therefore considered molecular crowding, where colloids with lower protein surface density demand a shorter incubation time than more crowded colloids. To test this, we grew and shrank colloid surface area. As the surface area shrank, the incubation time lengthened, while as it increased, the converse was true. These observations support a crowding effect on protein binding to colloidal aggregates. Implications for drug delivery and for detecting aggregation-based inhibition will be discussed. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|