Fig. 3: H3K36 and ssK36 peptides show different conformational preferences in solution. | Communications Chemistry

Fig. 3: H3K36 and ssK36 peptides show different conformational preferences in solution.

From: Mechanistic basis of the increased methylation activity of the SETD2 protein lysine methyltransferase towards a designed super-substrate peptide

Fig. 3

a Scheme of the FRET system. H3K36 and ssK36 peptides were synthesised with an EDANS fluorophore attached to the C-terminus and a Dabcyl quencher at the N-terminus. EDANS was excited at 340 nm and fluorescence emission was measured at 490 nm. Because of FRET, the fluorescence emission is partially quenched by Dabcyl, and only the remaining fluorescence was measured. The FRET experiments were conducted at multiple temperatures starting at 5 °C up to 95 °C using peptide concentrations of 10 µM. b At 5 °C, EDANS-H3K36-Dabcyl showed a 33% higher fluorescence intensity than EDANS-ssK36-Dabcyl. At 95 °C, both peptides displayed the same intensity (corresponding raw data are shown in Supplementary Fig. 3A). c Control experiment without quencher showed no temperature-dependent difference between EDANS-H3K36 and EDANS-ssK36 fluorescence. d Control experiment showed no difference in fluorescence intensity of EDANS-H3K36-Dabcyl and EDANS-ssK36-Dabcyl after their digestion with Proteinase K. In b–d, the fluorescence intensity of the ssK36 sample was normalised to the H3K36 sample. Data show average values of two independent experiments, error bars represent the deviation of the data points from the average.

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