Bacterial Microcompartment Shells made of BMC-H and BMC-T as a Function of pH

Bacterial microcompartments are self-assembling organelles that colocalize enzymes and metabolites of various biochemical pathways. Their selectively permeable shell is made entirely of protein, and the inherent properties of these systems make them attractive templates for bioengineering synthetic nanoreactors. Understanding the extent of shell stability in an extended range of conditions broadens the scope of chemistries that can be confined in these nanocompartments. Here, we analyze the stability of in vitro assembled BMC shells and find that they retain their structure at high concentrations of various solvents and detergents, at temperatures up to 75°C, and across a pH range from 3.9 to 11. Shell disassembly is observed below pH 3.9, but shells can be reassembled upon increasing the pH back to 8. These results expand the range of reactions that can be performed inside protein-based nanoreactors and underscore the potential of modular BMC shell proteins as versatile biomaterials.

pH: Sodium citrate buffers were made using the Hampton Research StockOptions Sodium Citrate Buffer Kit (pH 4.2–6.5) and titrating pH range 3.0–4.0 using HCl. HT shells were diluted to a final shell concentration of 1mg/mL in 50 mM sodium citrate buffer. CAPS buffer was prepared with CAPS reagent (Sigma-Aldrich) in Milli Q water. Sub-stock solutions of CAPS buffer pH 9.8–11 were prepared by adjusting the pH using NaOH. HT shells were diluted to a final concentration of 1 mg/mL in 50 mM CAPS buffer.

pH of each solution is listed as part of the name of the file

2026-05-29

2026-05-29

HT-SAXS

Advanced Light Source

SIBYLS BL12.3.1

1.23 Å

2.0 m

Samples: