In search of the perfect system

Researchers take a new approach to improve widely used biotechnology tool

The unique relationship between an essential vitamin and a purified bacterial protein has been used as a valuable tool in science and medicine for several decades. Together these two molecules, known as streptavidin and biotin, form a very strong and specific interaction that is invaluable for many biotechnological applications.

Labeling molecules with biotin and detecting them with streptavidin is a common part of many lab tests and has enabled many scientific discoveries in medicine. Streptavidin and biotin are as essential to lab technicians as hammers and nails are to a carpenter. The two molecules combine to form “molecular glue” for many of the tests used to diagnose infectious diseases like HIV, Hepatitis C and Lyme disease, to discover new proteins, viruses and bacteria, and to explore how molecules function in living organisms.

Read more on the Canadian Light Source website

Image: Trapped biotin: A crystal structure of the M88 mutein, determined at the CMCF beamline at CLS, reveals how the engineered disulphide formed between Cys49 and Cys86 (green spheres) partially block the exit pathway for biotin (magenta spheres). Credit: CLS