Synthesis of sulfur-35 reagents for protein labeling

摘要

Two ~(35)S reagents were developed to radiolabel proteins. The first reagent, a JV-hydroxysuccinimide (NHS) ester (SMSB), acylates the s-amino group of lysine residues in proteins. The second reagent, an aldehyde (MSAPPA), labels lysine residues via reductive alkylation. Comparing the two methods, the reductive alkylation method labeled proteins over a broader pH range with higher overall radiochemical yield. The biological activity of the proteins did not change Nter labeling with these ~(35)S reagents.