On the Relationship Between Residue Solvent Exposure and Thermal Fluctuations in Proteins

Structural characterization of holo- and apo-myoglobin in the gas phase by ultraviolet photodissociation mass spectrometry

“…Solvent accessibility is another physical parameter that has shown positive correlation with B -factors of proteins 51 , 52 as well as with ETD fragmentation trends for native proteins, 18 and thus was also evaluated in the context of the UVPD data in the present study. A plot of the solvent accessible surface area (SASA) for both the backbone and side chains generated from the ; 1DWR crystal structure is shown in Fig.…”

“…Tsai et al reported that the λ max of a typical alpha-helix occurred between 189–204 nm in solution with a molar absorptivity of 4.1 cm 2 mol × 10 –3 , whereas the molar absorptivities of coiled or loop regions were around 6.9 cm 2 mol × 10 –3 with a similar λ max (187–190 nm). 51 Interestingly, beta-sheets were reported to have an even greater molar absorptivity; 50 however, myoglobin contains no beta-sheets. 53 Although the exact mechanism of the UV activation and dissociation process for large molecules like proteins remains unknown in the gas phase, it is conceivable that local absorptivities of certain structural elements of proteins that are retained in the gas phase could have an impact on energy deposition and re-distribution prior to fragmentation.…”