A germin-like protein of wheat leaf apoplast inhibits serine proteases.
A protein resistant to heat and proteolysis that inhibits serine proteases was isolated from wheat leaf apoplasts. Based on trypsin inhibition, its more active form was a 66-69 kDa oligomer. It was dissociated in an 18-21 kDa monomer having an amino terminal sequence identical to the Box A of germins and germin-like proteins. Like these proteins, it was glycosylated and showed manganese superoxide dismutase activity. The monomer displayed three forms when examined by 2D western blot: two of 19 kDa, pI 5.8 and 6.2; and one of 21 kDa, pI 5.8. It was found that the protein controls serine protease activity in the apoplast of plants challenged with the fungus Septoria tritici.
Segarra
Carmen Inés
CI
Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, CC 1245, B7600GTQ, Mar del Plata, Argentina. segarra@mdp.edu.ar
Casalongué
Claudia Anahí
CA
Pinedo
Marcela Lilian
ML
Ronchi
Virginia Paola
VP
Conde
Rubén Danilo
RD
D000595:Amino Acid Sequence; D015153:Blotting, Western; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000378:metabolism* / Q000494:pharmacology; D018515:Plant Leaves / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism* / Q000494:pharmacology; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism; D014908:Triticum / Q000378:metabolism*; D014357:Trypsin / Q000187:drug effects / Q000378:metabolism
D006023:Glycoproteins; D010940:Plant Proteins; D015842:Serine Proteinase Inhibitors; C058814:germin; D013482:Superoxide Dismutase; D014357:Trypsin