Effect on epidermal cell of soybean protein-degraded products and structural determination of the root hair promoting peptide.
Peptide(s) produced from degraded soybean protein by an alkaline protease from Bacillus circulans HA12 (degraded soybean-meal products; DSP) increased the number of both the root hair cells (trichoblasts) and hairless cells (atrichoblasts) of Brassica rapa by about 4.4 times and 1.9 times, respectively. To identify the root hair-promoting peptide(s) in DSP, the origin protein of the root hair-promoting peptide(s) was identified as Kunitz trypsin inhibitor (KTI). The root hair-promoting peptide in the degraded products of KTI was purified and produced a signal of 1,198.2 Da with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. A search of the amino acid sequence of KTI located the peptide GGIRAAPTGNER, which had a molecular weight identical to 1,198.2 Da. The peptide GGIRAAPTGNER was chemically synthesized, and the synthetic peptide possessed root hair-promoting activity. Thus, it is concluded that this peptide in DSP is the foreign bioactive peptide promoting the differentiation of root hairs.
Department of Bioscience and Technology, Faculty of Science and Engineering, Ritsumeikan University, Nojihigashi, Kusatsu, Shiga, Japan.
Yoshiki
Y
Matsumiya
Sayoko
S
Sumiyoshi
Takuma
T
Matsukura
Motoki
M
Kubo
D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D019441:Plant Epidermis / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D030262:Soybean Proteins / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000737:chemistry / Q000378:metabolism
D010455:Peptides; D030262:Soybean Proteins; D014360:Trypsin Inhibitor, Kunitz Soybean