title: Purification, characterization and cloning of antiviral/ribosome inactivating protein from Amaranthus tricolor leaves.
abstract: An antiviral protein (AVP), imparting high level of resistance against sunnhemp rosette virus (SRV) was purified from the dried leaves of Amaranthus tricolor. The purified protein (AAP-27) exhibited approximately 98% inhibition of local lesion formation at a concentration range of approximately 30 microg ml(-1). The protein was found to be highly basic glycoprotein monomer (pI approximately 9.8) of Mr 27 kDa, with neutral sugar content of 4%. The purified protein exhibited N-glycosidase and RNase activities. We have also isolated full-length cDNA clone, encoding this protein designated as A. tricolor antiviral protein-1 (AAP-1). Two primers, one designed on the basis of N-terminal sequence of the purified protein and the other from the conserved active peptides of other AVPs/RIPs were used for PCR amplification of double stranded cDNA, isolated from the leaves of A. tricolor. The amplified fragment was used as a probe for library screening. The isolated full-length cDNA consisted of 1058 nucleotides with an open reading frame encoding a polypeptide of 297 amino acids. The deduced amino acid sequence of AAP-1 has a putative active domain conserved in other AVPs/RIPs and shows varying homology to the RIPs from other plant species.
authors.affiliation: Division of Biochemistry, Indian Agricultural Research Institute, New Delhi 110012, India.
authors.forename: Sribash
authors.initials: S
authors.lastname: Roy
authors.forename: P
authors.initials: P
authors.lastname: Sadhana
authors.forename: Mehbuba
authors.initials: M
authors.lastname: Begum
authors.forename: Sushil
authors.initials: S
authors.lastname: Kumar
authors.forename: M L
authors.initials: ML
authors.lastname: Lodha
authors.forename: H C
authors.initials: HC
authors.lastname: Kapoor
mesh_terms: D027721:Amaranthus / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D003609:Dactinomycin / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006026:Glycoside Hydrolases / Q000378:metabolism; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018515:Plant Leaves / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012260:Ribonucleases / Q000378:metabolism; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid
chemical_list: D000998:Antiviral Agents; D018076:DNA, Complementary; D010940:Plant Proteins; D003609:Dactinomycin; D012260:Ribonucleases; D006026:Glycoside Hydrolases