Just a curious question, if we extract restriction enzyme and inject it to our body, what happen?
- Does antibody recognize and block it?
- Can restriction enzyme pass over cell membrane and destroy the DNA of a living cell ?
The appearance of any foreign antigens (e.g., proteins like restriction enzymes fall n this category) in the circulatory system should trigger an immune response.
There are actually two membrane barriers that the enzymes have to traverse to gain access to the nuclear genome: the cell membrane, and the nuclear membrane. Proteins are typically too large and too charged to cross a lipid bilayer membrane--unless there is a pore (like on the nuclear membrane) or receptor for the protein on the cell surface.
When cells are engineered to express foreign restriction enzymes using transgenes, then yes, if the protein can enter the nucleus then the enzyme will start to digest all of its recognition sites.
Jasper Rine demonstrated this for the Baker's Yeast S. cerevisiae in 1986.