Optimizing protein expression is a key step for NMR spectroscopy, which typically requires milligram quantities of isotope-labeled protein.Human cardiac troponin I (cTnI) is a 210-amino acid protein that accumulates in intracellular inclusion bodies when overexpressed in E. coli. Our initial attempts at producing an isolated N-terminal fragment, cTnI[1-71], resulted in negligible expression. This was due to proteolytic degradation, as evidenced by the expression of a fusion construct, GB1-cTnI[1-71], yielding GB1 alone. In order to target cTnI[1-71] to inclusion bodies, we fused it to Comamonas testosteroni ketosteroid isomerase (KSI), a hydrophobic 125-amino acid protein, using the commercially available pET31b expression vector.The KSI-cTnI[1-71] fusion protein was expressed in inclusion bodies and purified to a reasonable yield. However, when a tandem dimer, KSI-cTnI[1-71]-cTnI[1-71], was expressed, only a single band corresponding to the molecular weight of KSI alone was observed, suggesting that it was susceptible to intracellular proteases.Beta barrel proteins of the Gram negative bacterial outer membrane accumulate in inclusion bodies when overexpressed without their N-terminal signal sequence. A fusion construct involving the E. coli outer membrane enzyme, PagP, (PagP-cTnI[1-71]) expressed robustly in inclusion bodies. Moreover, the tandem dimer, PagP-cTnI[1-71]-cTnI[1-71], also expressed well.Using a beta barrel protein as a fusion partner has several theoretical advantages for expressing intrinsically disordered proteins. There is no possibility for the protein to fold outside of the membrane environment. Furthermore, beta barrel membrane proteins are not extremely hydrophobic, since the interior of the barrel is typically hydrophilic. Hydrophobic proteins tend to have limited yield, can be toxic to cells, and may interfere with later purification or processing steps. Thus fusion to PagP or other beta barrel membrane proteins represents a promising new alternative for difficult-to-express disordered proteins.