Bio-syringe technology for protein delivery

11 Dec 2015 NUS scientists discovered 100% efficiency of protein delivery into cells by Agrobacterium bio-syringe with a new bio-imaging method.

Proteins can provide a wide range of functions. Their usage for a biological system is limited, as they cannot diffuse through cell membranes because of the large sizes. Reagent-facilitated delivery of proteins into cells is useful; it requires a laborious process of protein production and purification before the delivery. Introduction of the genes encoding the proteins is an alternative approach to use proteins; but genetic modification raises safety and environmental concerns.

A research team led by Prof PAN Shen Quan from the Department of Biological Sciences in NUS has demonstrated that Agrobacterium tumefaciens can deliver proteins into recipient cells at an efficiency of up to 100%. The bacterium can produce and deliver protein molecules that are functional inside the host cells.

This indicates that the bacterium can be developed as a bio-syringe for protein delivery, which does not require additional process for protein production and purification. This will certainly change the thinking of related researchers. It also opens up a new field: studies of the “logistics” and trafficking of protein complex delivered by Agrobacterium bio-syringe, which is efficient and can be used for diverse hosts. This will lead to using a bio-syringe to deliver proteins and study how they function in recipient cells.

The research team has embarked on a program to develop bio-syringe technology for protein delivery. Agrobacterium-based vectors will be developed to deliver various proteins; bio-syringe libraries will be constructed to test the functions of proteins. The team will study how bio-syringe-delivered proteins traffick inside recipient cells. More importantly, the team will analyse post-translational modifications of bio-syringe-delivered proteins for glyco-engineering and develop bio-syringe-based systems to trigger plant resistance to diseases and to regulate plant development.

PanSQ 2

A split-GFP approach to visualize Agrobacterium-delivered VirE2 protein. [Image credit belongs to: Li Xiaoyang]

PanSQ 1 

A large amount of VirE2-GFP protein can be delivered into each plant cell. [Image credit belongs to: Yang Qinghua]



Li X, Yang Q, Tu H, Lim Z, Pan SQ. “Direct visualization of Agrobacterium-delivered VirE2 in recipient cells.” The Plant Journal. 77 (2014) 487.