ISOLATION, PURIFICATION AND CHARACTERIZATION OF SERINE PROTEASE INHIBITOR PRODUCING ENDOPHYTIC FUNGUS Penicillium chrysogenum sp. AZX2011

The endophytic fungus Penicillium chrysogenum sp. AZX2011 was isolated from the medicinal plant
Lawsonia inermis. The phylogenetic study of isolated fungus was carried out by 18s rRNA analysis.
The partial sequence of 18s rRNA was submitted to the Gen bank database which allotted accession
number KU253718.1. This fungal species produces a strong serine protease inhibitor (SPI) which
showed inhibition against trypsin as a model enzyme. Purity of purified SPI was confirmed by SDSPAGE
(Sodium Dodecyl Sulphate-Polyacrylamide gel electrophoresis) and MALDI-TOF (Matrixassisted
laser ionization- time-of-flight mass spectrometer) with molecular weight 18.5 kDa. Serine
protease inhibitor (SPI) was found to be stable from pH 4.0 to pH 10.0 and temperature 25°C to
60°C. However, this trypsin inhibitor did not show any anti-protease activity against other proteases
like papain, metallo-proteases and pepsin.