Every field has its legends..turns out protein engineering does too! We just released our 1st Edition Protein Engineering Trading Cards, highlighting a few of our everyday workhorses!

Introducing the line-up:

#24 Glycine-Serine Linker: a flexible utility player connecting antibody domains

#05 Mouse IgK Signal Peptide: the secretion specialist guiding proteins out of the cell

#17 Disulfide Bond: the offensive line holding structures together under pressure

#82 Immunoglobulin Domain: a modular fold reused across the immune system

These elements are all commonly used in antibody and therapeutic design, and a few are also common fixtures more generally in protein design and enzyme engineering.

Glycine-Serine (Gly-Ser) linkers are peptide sequences that consist of repeats glycine and serine amino acid residues, often (GGGS)n, that can range in length from 2 to ~20 residues. These are sometimes even longer, but the longer the sequence, the less stable the overall molecule usually becomes (so add with care!). This linker composition a favorite go-to because it creates a flexible peptide chain with minimal side chain interference. Glycine-Serine linkers are found in CARs, bispecifics, and fusion proteins, and are also applied to synthetic biology use cases for creating flexibility and fusing desired functional domains.

The mouse IgK signal peptide is derived from the mouse