In vivo protein transduction: Delivery of a biologically active protein into the mouse

Delivery of therapeutic proteins into tissues and across the blood-brain ba rrier is severely limited by the size and biochemical properties of the pro teins. Here it is shown that intraperitoneal injection of the 120-kilodalto n beta-galactosidase protein, fused to the protein transduction domain from the human immunodeficiency virus TAT protein, results in-delivery of the b iologically active fusion protein to all tissues in mice, including the bra in. These results open new possibilities for direct delivery of proteins in to patients in the context of protein therapy, as well as for epigenetic ex perimentation with model organisms.