Taq DNA polymerase consists of isolated functional domains responsible for binding of template DNA and catalysis of DNA synthesis, respectively. Previous research showed that the DNA-binding domain can be replaced by other protein or motif with higher DNA-binding affinity, resulting a modification in several properties of the recombinant polymerase．In the present study, a recombinant Taq DNA polymerase was constructed by replacing the N-terminal 289 amino acids of Taq DNA polymerase with cationic peptide of human lactoferrin (NL-N)．Some enzymatic properties of the chimerical recombinant DNA polymerase, such as the processivity, 5'-3' exonuclease activity, and tolerance to serum concentration in PCR reaction system, were characterized experimentally and the testing data showed that the modification of DNA-binding domain with NL-N improved the polymerase in several aspects.
