Abstract: Methods for purifying DNA repair enzymes are provided in which an aqueous solution of a DNA repair enzyme in an impure state is applied to a molecular sieve column having an exclusion limit which will retard the DNA repair enzyme but will not retard contaminants larger than the DNA repair enzyme. The DNA repair enzyme in an enhanced state of purity is eluted isocratically from the molecular sieve column in an elution buffer and applied directly to a DNA affinity column in the same buffer without intermediate dialysis, ultrafiltration, or other procedures. The DNA repair enzyme is eluted from the DNA affinity column using, for example, a salt gradient. The method is rapid, inexpensive, simple to perform, and has been found to produce a homogeneous final product. In accordance with other aspects of the invention, the purified DNA repair enzymes are encapsulated in liposomes and administered to living cells in situ.

Abstract: Methods for purifying DNA repair enzymes are provided in which an aqueous solution of a DNA repair enzyme in an impure state is applied to a molecular sieve column having an exclusion limit which will retard the DNA repair enzyme but will not retard contaminants larger than the DNA repair enzyme. The DNA repair enzyme in an enhanced state of purity is eluted isocratically from the molecular sieve column in an elution buffer and applied directly to a DNA affinity column in the same buffer without intermediate dialysis, ultrafiltration, or other procedures. The DNA repair enzyme is eluted from the DNA affinity column using, for example, a salt gradient. The method is rapid, inexpensive, simple to perform, and has been found to produce a homogeneous final product. In accordance with other aspects of the invention, the purified DNA repair enzymes are encapsulated in liposomes and administered to living cells in situ.

Abstract: A method for administering a protein having intracellular biological activity into the interior of living skin cells, which lie below the skin's stratum corneum, is provided. The method comprises the steps of: (a) encapsulating the protein in liposomes; and (b) applying the liposomes to the outer surface of living skin so that the protein encapsulated in the liposomes traverses the skin's stratum corneum and the outer membranes of said cells and is thereby delivered by the liposomes into the interior of said cells. In certain preferred embodiments, the liposomes are pH sensitive liposomes. In other preferred embodiments, the protein is a DNA repair enzyme, such as T4 endonuclease V.

Abstract: Methods for purifying DNA repair enzymes are provided in which an aqueous solution of a DNA repair enzyme in an impure state is applied to a molecular sieve column having an exclusion limit which will retard the DNA repair enzyme but will not retard contaminants larger than the DNA repair enzyme. The DNA repair enzyme in an enhanced state of purity is eluted isocratically from the molecular sieve column in an elution buffer and applied directly to a DNA affinity column in the same buffer without intermediate dialysis, ultrafiltration, or other procedures. The DNA repair enzyme is eluted from the DNA affinity column using, for example, a salt gradient. The method is rapid, inexpensive, simple to perform, and has been found to produce a homogeneous final product. In accordance with other aspects of the invention, the purified DNA repair enzymes are encapsulated in liposomes and administered to living cells in situ.