Here, we tested whether the shorter chain PEG in conjugated Gal3C-PEG 550 Da also formed a shroudlike conformation by measuring the τc value for Gal3C-PEG 550 Da. Unlike Gal3C-PEG 5 kDa, we determined a τc value for Gal3C-PEG 550 Da to be 10.6 (±1.0) ns, which is similar to the τc value measured for Gal3C and significantly shorter than the τc value measured for Gal3C-PEG 5 kDa (Figure , Section ). The similar τc values for Gal3C and Gal3C-PEG 550 Da are consistent with similar linewidths observed in their respective N-edited 1 H NMR spectra (Figure ). Together, these data support a shroud-like model for Gal3C-PEG 5 kDa and a more dumbbell-like model for Gal3C-PEG 550Da. excited, or first-to-second excited states respectively. In all spectra, an elongated peak shape across the amide I stretching region is observed with two main peak centers near 1630 and 1680 cm -1 , corresponding