Sandbox454

This is a default text for your page Sandbox454. Click above on edit this page to modify. Be careful with the < and > signs.

You may include any references to papers as in: the use of JSmol in Proteopedia ^[1] or to the article describing Jmol ^[2] to the rescue.

Structure and Function

Pembrolizumab, or Keytruda, is an immunoglobulin G4 (IgG4)-kappa humanized monoclonal antibody against the programmed cell death-1 (PD-1) receptor. It is a very compact molecule with an asymmetrical Y-shape. The short compact hinge region inflicts constraints on the molecule that creates the abnormal crystallizable tail region (Fc domain) compared to other immunoglobulin G (IgG) proteins. The Fc domain is glycosylated at both CH2 domains on each chain and one of them is distinctively rotated 120° compared to other similar structures, making the glycan chain more solvent accessible and facing the solvent. IgG4s have a unique function where they form dynamic bispecific antibodies by exchanging half-molecules (one heavy chain/light chain pair) among themselves, called Fab-arm exchange. This makes the molecule particularly unstable and unpredictable as a treatment, but can be conquered by introducing a serine-to-proline mutation at amino acid 228, which prevents Fab-arm exchange and stabilizes the molecule<ref/1>.

Pembrolizumab/PD-1 Interaction

PemFab/PD-1 Interaction

PemFv/PD-1 Interaction

Mechanism

This is a sample scene created with SAT to by Group, and another to make of the protein. You can make your own scenes on SAT starting from scratch or loading and editing one of these sample scenes.