NOVEL HIRUDINE VARIANT, PROCESS FOR PRODUCING THE SAME, AND ANTICOAGULANT CONTAINING THE SAME AS ACTIVE INGREDIENT.

摘要

A hirudine variant having the sequence represented by the sequence identification number 1. A DNA coding for the amino acid sequence of the variant, an expression vector, a recombinant colon bacillus, and a process for producing the variant by using the bacillus. An anticoagulant containing the variant as the active ingredient. Because this variant is deficient in the sequence Asp<3><3>-Gly<3><4>- or Asp<6><2>-Ala<6><3>- contained in the amino acid sequences of the conventional hirudine and variants thereof, it can inhibit the formation of the succinimide derivative and beta -transfer derivative otherwise caused by the above sequence and has a high stability and a high antithrombine activity, thus being useful as an anticoagulant. Furthermore, a hirudine variant having the sequence represented by the sequence identification number 1, wherein the sequence VAl<1>-VAl<2>- contained in the amino acid sequence of the conventional hirudine variants has been replaced by the sequence Ile<1>-Ile<2>-, has a significantly high antithrombin activity especially suitable for the use as an anticoagulant.