Abstract: The present invention provides a covalent conjugate. The conjugate includes an antibody or antibody derivative, at least two LL37-derived polypeptides, and a payload. The antibody or antibody derivative targets a cell that has phosphatidylserine in its outer leaflet. The payload includes: a small molecule cytotoxic drug of less than 3 kDa, or a plurality thereof; or a peptide or protein of less than 100 kDa. Uses and methods of using these covalent conjugates are also provided, related to enhancing delivery of the antibody/derivative or the payload, e.g. to enhance therapeutic or diagnostic effectiveness.

Abstract: A secretion signal peptide sequence (SP) in combination with a cleavage inhibition sequence (CIS) fused to a structural gene sequence in a recombinant expression system can be used to express a full length protein with an SP in a cell. Such a fusion protein may be purified to homogeneity from a membrane fraction of the cell. The SP in combination with the CIS is a protein transduction domain that exhibits superior intracellular protein transduction efficiency when the SP precedes the CIS in a N to C-terminus direction.

Abstract: A secretion signal peptide sequence (SP) in combination with a cleavage inhibition sequence (CIS) fused to a structural gene sequence in a recombinant expression system can be used to express a full length protein with an SP in a cell. Such a fusion protein may be purified to homogeneity from a membrane fraction of the cell. The SP in combination with the CIS is a protein transduction domain that exhibits superior intracellular protein transduction efficiency when the SP precedes the CIS in a N to C-terminus direction.