Bacterial Protein Production System



The invention is a bacterial system uniquely suited for the expression of membrane proteins that takes advantage of
an unusual attribute of the bacterium Rhodospirillum rubrum. R. rubrum can express foreign proteins where other
common bacterial systems fail.

Target Problem

Many membrane proteins and others are difficult to produce in systems like E. coli, often killing the host or yielding
inactive, improperly folded proteins. R. rubrum which has an extensive intracytoplasmic membrane (ICM) that helps
it to produce external proteins.

Key Benefits

Versatile – Can be used to express and purify multiple types of membrane proteins, including human
membrane proteins

High Yield – Potential for efficient, large-scale production for non-infectious vaccines, protein
therapeutics, enzyme therapies, and basic research

Simple Purification – ICM is readily separated from other cellular material, easing membrane protein

Low Cost – System induced by reduced oxygen concentration, a simple, low-cost stimulus applicable to
both laboratory and production scales

SafeR. rubrum is non-pathogenic to humans and grows on simple media

Intellectual Property

U.S. Patent 6,680,179
U.S. Patent 6,951,741
U.S. Patent 8,481,287

This technology is seeking partners for development of the final product. Several academic and pharmaceutical based laboratories have tested or are currently testing the kit for efficacy.  It is available licensing under either exclusive or non-exclusive terms.


Butzin, N.C; Owen, H.A.; and M.L.P. Collins. 2010. A new system for heterologous expression of membrane proteins: Rhodospirillum rubrum. Protein Expression and Purification, 70: 88-94.

Inventor (s)

Dr. M.L.P. Collins is a Professor Emerita in the Department of Biological Science at UWM specializing in Microbial physiology. She earned a Ph.D. in Microbiology from Rutgers University and was a Postdoctoral Fellow at NYU School of Medicine.