BS3-d4 (Bis[Sulfosuccinimidyl] 2,2,7,7-suberate-d4)
from
Thermo Scientific Pierce Protein Research Products
Description
Heavy (-dn) and light (-d0) cross-linking reagent analogs are reacted simultaneously with the target protein or protein complex. Incorporating deuterium at discrete positions in the cross-linking reagent allows both protein cross-linking and protein labeling to occur in a single step. Use of heavy/light cross-linker pairs in this application simplifies the MS identification of the peptides resulting from the coupling reactions. Application of a 1:1 ratio of two identical cross-linking agents differing only in the number of deuterium atoms in their chemical composition (e.g. d4 vs d0) is a powerful identifier of low abundant singly cross-linked peptides in the mass spectrometer. The reagents introduced here will generate MS patterns in which the resultant cross-linked peptides will differ by 4 mass units after enzymatic digestion of the cross-linked protein or protein complex. Further analysis of the reaction products can yield low resolution three dimensional structure information. Intermolecular cross-linking of an interacting protein complex and MS analysis have been successfully applied to determine the molecular contact surfaces of binding partners in a protein complex.