Purification and characterization of a new antiviral protein from
the leaves of Pandanus amaryllifolius (Pandanaceae)
Linda S. M. Ooi, Samuel S. M. Sun, Vincent E. C. Ooi∗
Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
Accepted 21 January 2004
Abstract
A lectin, designated Pandanin, was isolated from the saline extract of the leaves of Pandanus amaryllifolius, using ammonium
sulfate precipitation, affinity chromatography on mannose–agarose and molecular size exclusion by gel filtration.
Pandanin is an unglycosylated protein with a molecular mass of 8.0 kDa both after gel filtration and on sodium dodecyl
sulfate-polyacrylamide gel electrophoresis, indicating that it is a single polypeptide chain. The first 10 residues of the
N-terminal amino acid sequence are DNILFSDSTL. An analysis of the sequence of first 30 amino acids at the N-terminal
region shows that Pandanin has about 50–60% homology to those of mannose-specific lectins reported from monocot plants.
Pandanin exhibits hemagglutinating activity toward rabbit erythrocytes, and its activity could be reversed exclusively by mannose
and mannan. Pandanin also possesses antiviral activities against human viruses, herpes simplex virus type-1 (HSV-1)
and influenza virus (H1N1) with 3 day’s EC50 of 2.94 and 15.63M, respectively.
© 2004 Published by Elsevier Ltd.