and : Critical Residues for In Vitro Biological Activity of Reteplase

Autor: Sunil Kumar Tandra, Naganath Mandi, Suman Bandyopadhyay, Kalyana R. Sundaram, Sriram Padmanabhan
Rok vydání: 2010
Předmět:
Zdroj: Advances in Hematology. 2010:1-9
ISSN: 1687-9112
1687-9104
DOI: 10.1155/2010/172484
Popis: Reteplase (rPA) is a thrombolytic agent used for the treatment of acute myocardial infarction. We studied the expression of rPA and its selected asparagine mutants after integration into the Pichia genome. Though methanol induction of the native and the rPA mutants showed similar expression levels (~200–250 mg/L), the mutants displayed significant loss of protease activity. Strikingly, the clot lysis activities of these mutants were considerably different. While mutation of A s n 1 2 (N12P) of the Kringle 2 domain showed delayed clot lysis activity ( 𝑡 1 / 2 = 3 8 min) compared to the native rPA ( 𝑡 1 / 2 = 3 3 min), a faster rate of clot lysis ( 𝑡 1 / 2 = 2 7 min) was observed when the A s n 2 7 8 (N278S) of the serine protease domain was mutated. Interestingly, the slowest clot lysis activity ( 𝑡 1 / 2 = 4 9 min) demonstrated by the double mutant (N12P, N278S) suggests the dominant role of A s n 1 2 in regulating the fibrinolytic activity of rPA. The results presented in this paper indicate that the fibrinolytic and the proteolytic activities of rPA are independent of each other.
Databáze: OpenAIRE