Maha B. Dafalla1 ; Reem. M. A. Ebrahim1 ; Nehad M. Abdulaziz1 ; Sara A. A. Elmubarak1 ; Eva H. Naser1 , Yusria E. Abdelrahim1 , Entsar A. Abdalrhman1 , Ahmed H. Idries1 ; Makarim, E. M. Osman1 , Ghada, H. Ali2 , Ahmed k. bolad3 ; Atif A. Elagib4 and Emadeldin H. Konozy1*
الملخص الانجليزي
Lectins are defined as the carbohydrate-binding proteins of non-immune origin
that can interact and precipitates glycoconjugates from their solutions. Due to
these features, many applications have been discovered for these proteins. The
present investigation has been devoted to optimising a protocol for the extraction,
purification and characterization of a lectin from the seeds of the medicinal plant
Ocimum basilicum (OBSL). Different extraction procedures were employed,
including varying buffers with variable pHs. Precipitation of the seeds' crude
protein extract with salting-out using solid ammonium sulphate (AmS) at 40, 60
and 80% concentrations resulted in the segregation of the lectins into at least
three isoforms. The lectin was purified to apparent electrophoretic homogeneity
by fetuin-agarose affinity resin. The lectin was a trimer composed of three
subunits of different molecular weights. Scanning the three AmS precipitated
protein fractions at the UV ranges, indicates that the protein is rich in tryptophan
rather than tyrosine. The lectin haemagglutination pattern studies showed that
OBSL had a better affinity for the B+ human blood group, sheep and rabbit
erythrocytes as compared to other human and animal blood types. The lectin was
not inhibited by any simple sugar indicating its classification as a lectin with
complex sugar specificity. OBSL was stable within the pH range from 2.5 to 10.5
showing two pH activity optima. It was optimally active from 40 to 50 °C. This
study represents the first-ever report on this plant lectin and might stimulate
further studies to extensively characterize this protein.
يسرية الشيخ عبدالرحيم عبدالواحد | Yusria Elshiekh Abdalrahim Abdalwahed | 316