ANTIMICROBIAL ACTIVITY OF LECTIN ISOLATED FROM EGYPTIAN WHEAT CULTIVAR GIZA 171

Abstract

In the current study crude lectin was isolated from Egyptian wheat seeds cultivarGiza 171 and it was characterized by several methods such as sodium dodecyl sulfate-polyacrylamidegel electrophoresis (SDS-PAGE), Native-PAGE, Iso-electric point evaluation, Fourier transforminfrared (FTIR) spectroscopy and amino acids composition. Furthermore, antibacterial and antifungalactivities were estimated against some gram positive, gram negative bacteria and pathogenic fungus.Based on Native-PAGE (unreduced) of wheat seeds lectin indicates one major band with a molecularweight of approximately 50 kDa. SDS-PAGE of wheat seeds lectin separated this high molecularweight band into 2 bands corresponding to smaller molecular weights (14,20 kDa). The iso-electricpoints were deduced from the protein pH-solubility curve. It is clear that the least soluble points wereobtained at pH 5.5. The content of the hydrophobic amino acids residues (proline, valine, isoleucine,leucine and phenyl alanine) valued 27.8% and this represent 31.1% of the total amino acids. Theminimum inhibitory concentrations (MIC) of lectin against L. monocytogenes and P. aeruginosa was800 μg/ml, 1600 μg/ml for B. subtillis and 3200 μg/ml against E. coli. Lectin inhibited mycelialgrowth of F. oxysporun and F. solani at a wide concentration range (250, 500 and 1000 μg/ml). Thisstudy has elucidated that the lectin isolated from wheat seeds cultivar Giza 171 have the potentantibacterial and antifungal activities against selected pathogenic bacteria and fungai.