Abstract: The present disclosure is directed to new methods and systems performing flexible and reversible modification of DNA in order to establish the logical value of true or false for a set of clauses. It combines both the biological meaning and experimental procedure with the logical implementation of the basic Boolean operators: OR, AND, and NOT. A feature of methylation logic is the use of the reversibility of DNA methylation of cytosine and adenine. Logic variables can be negated by reversing the DNA methylation status. Four implementation scenarios are described: three of them use methyl-sensitive restriction enzymes and the fourth uses methyl-binding proteins. Encoding can use either single or double stranded DNA. In addition, the disclosure allows for solving a multi-variable SAT problems by implementing a logic circuit.

Abstract: A cloned cDNA containing complete coding sequence for the expression of a protein with all properties of the precursor to human procathepsin L is described. All of the protein's major domains, including the pre, pro, and carboxyterminal extensions are represented in the full length cDNA sequence of the present invention.