Wounding induces a series of closely related trypsin/chymotrypsin inhibitory peptides in leaves of tobacco.
Wounding of tobacco (Nicotiana tabacum) leaves induced the expression of acid-stable trypsin/chymotrypsin inhibitory activity. Analysis by gel filtration determined that the inhibitory activity was contained within a fraction with a native M(r) of ca 5-7 x 10(3). Using ion-exchange column chromatography, this was resolved further into two major fractions, each of which inhibited both trypsin and chymotrypsin. Reverse-phase HPLC identified a total of six peptides from both fractions and each was purified to homogeneity. Four of these peptides inhibited both trypsin and chymotrypsin, a fifth inhibited trypsin only, while the sixth inhibited chymotrypsin almost exclusively. Sequencing of the N-terminal revealed that each peptide had an identical amino acid sequence and that these proteins are similar to a series of trypsin/chymotrypsin inhibitory peptides that are expressed predominantly in the stigmas of Nicotiana alata flowers.
McManus
M T
MT
Plant Molecular Genetics Laboratory, Grasslands Research Centre, Palmerston North, New Zealand.
Laing
W A
WA
Christeller
J T
JT
D000595:Amino Acid Sequence; D002852:Chromatography, Ion Exchange; D002918:Chymotrypsin / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D010947:Plants, Toxic; D014026:Nicotiana / Q000502:physiology*; D014361:Trypsin Inhibitors / Q000096:biosynthesis* / Q000302:isolation & purification
D010940:Plant Proteins; D014361:Trypsin Inhibitors; D002918:Chymotrypsin