FabDELLO

FabDELLO is a protease that specifically digests human IgG1 at a single site above the hinge, yielding intact Fab and Fc fragments within two hours with no need for reducing conditions.

The enzyme is active on antibodies with mutated hinge regions, such as the LALA mutation, and enables middle-level LC-MS for characterization of critical quality attributes on antibodies with mutated hinges.

FabDELLO is available as a lyophilized enzyme in 8 x 100 units strips or 96 x 100 units plates.

The FabDELLO Enzyme

FabDELLO digests human IgG1 at a single site above the hinge (...KSCDK / THTCPPCP…), generating intact Fab and Fc fragments. A second digestion site may appear on the Fc if the N-glycans are removed. FabDELLO is active under native conditions and requires the presence of calcium ions. Optimal activity is obtained at 37°C and pH 7-8.5.

FabDELLO is cloned from Bdellovibrio bacteriovorus and expressed in E. coli. The enzyme contains a His-tag and the molecular weight is 32 kDa.

Unit Definition

One unit FabDELLO digests ≥ 90% of 1 ug human IgG1, when incubated in Tris buffered saline (TBS), pH 7.6, containing 10 mM CaCl₂, at 37°C for 2 h.

Content and Storage

FabDELLO is supplied lyophilized in 50 mM Tris-HCl, 150 mM NaCl, pH 7.6, with no preservatives added. It is available in 8 x 100 units or 96 x 100 units strip wells, each well digesting 100 µg human IgG1. FabDELLO is supplied with 1 vial 20x CaCl₂ solution (200 mM).

FabDELLO is shipped cold and should be stored at -20°C upon arrival. Since FabDELLO has autoproteolytic activity, the enzyme should be kept cold and used the same day as reconstitution.

FabDELLO is for R&D use only.