Louisa Smieska and Ruth Mullett studied manuscript pages from Cornell University Library’s Division of Rare and Manuscript Collections (RMC), dating from the 13th to the 16th centuries, using X-ray fluorescence (XRF) and spectral imaging analysis.

“Our initial goal was to learn more about Cornell’s fragments and about trends in pigment use,” said Mullett, a medieval studies doctoral student. “An initial survey using a portable point XRF [p-XRF] instrument uncovered several things we weren’t expecting.”

Integral membrane proteins, or IMPs, are a major class of proteins that play crucial roles in many cellular processes, including the catalysis of disulfide bonds, which are essential for the function and stability of many proteins such as antibodies, which have significant therapeutic potential.

But IMPs are intrinsically hydrophobic and thus have low solubility in watery environments. Their natural environment is within the lipid bilayer membrane of a cell, which makes it difficult to study their structure and function.