In vitro thrombolytic activity of purified streptokinase extracted from Streptococcus equinus VIT_VB2 isolated from bovine milk

J Thromb Thrombolysis. 2015 Jan;39(1):71-8. doi: 10.1007/s11239-014-1093-2.

Abstract

Streptokinase (SK) is an extracellular enzyme secreted by various strains of β-hemolytic Streptococci. The main focus of the current study is to evaluate the in vitro thrombolytic activity of purified SK extracted from Streptococcus equinus VIT_VB2 (Accession no. JX406835) isolated from milk sample. The growth rate of S. equinus VIT_VB2 strain was studied with pH and biomass content which has positive significant effect on enzyme yield. A temperature of 10 °C and pH of 6 was found to be optimum for maximum SK activity. The specific activity of the purified SK produced by VIT_VB2 strain was found to be 6,585 IU mg(-1). The molecular mass of the enzyme was determined as 47 kDa by SDS-PAGE. In vitro thrombolytic activity of purified SK was determined using synthetic chromogenic substrate S-2251, the activity of the purified enzyme was found to be 6,330 ± 2.2 IU. The purity of SK was compared with standard SK by HPLC. This is the first report which reveals the SK activity of S. equinus isolated from milk sample.

MeSH terms

  • Animals
  • Bacterial Proteins* / chemistry
  • Bacterial Proteins* / isolation & purification
  • Bacterial Proteins* / pharmacology
  • Cattle
  • Female
  • Fibrinolysis / drug effects*
  • Fibrinolytic Agents* / chemistry
  • Fibrinolytic Agents* / isolation & purification
  • Fibrinolytic Agents* / pharmacology
  • Humans
  • Male
  • Milk / microbiology*
  • Streptococcus equi* / enzymology
  • Streptococcus equi* / isolation & purification
  • Streptokinase* / chemistry
  • Streptokinase* / isolation & purification
  • Streptokinase* / pharmacology

Substances

  • Bacterial Proteins
  • Fibrinolytic Agents
  • Streptokinase