TY - JOUR
T1 - N-terminal mutational analysis of the interaction between growth-blocking peptide (GBP) and receptor of insect immune cells
AU - Watanabe, Satoshi
AU - Tada, Masahito
AU - Aizawa, Tomoyasu
AU - Yoshida, Masanobu
AU - Sugaya, Tadamasa
AU - Taguchi, Makoto
AU - Kouno, Takahide
AU - Nakamura, Takashi
AU - Mizuguchi, Mineyuki
AU - Demura, Makoto
AU - Hayakawa, Yoichi
AU - Kawano, Keiichi
PY - 2006
Y1 - 2006
N2 - GBP, a small insect cytokine isolated from lepidopterans, has a variety of functions. We constructed a series of mutants focusing on the unstructured N-terminal residues of GBP by acetylation, deletion, and elongation in order to investigate the interaction between GBP and its receptor in plasmatocytes. The 1H NMR spectra showed no significant changes in the tertiary structures of these peptides, which indicated that all the mutants maintained their core β-sheet structures. The deletion and acetylated mutants, 2-25GBP, Ac2-25GBP, and AcGBP, lost their activity. 2-25GBP was the strongest antagonist, while Ac2-25GBP and AcGBP were moderate. In contrast, the elongated mutants, (-1R)GBP, (-1A)GBP, and (-2G,-1R)GBP maintained their plasmatocyte-spreading activity. These results demonstrate the importance of the GBP N-terminal charged amine and length of N-terminal GBP-peptide backbone for plasmatocyte-spreading activity. Next, we analyzed other mutant peptides, 1-25(N2A)GBP and 2-25(N2A)GBP, focusing on Asn2. Surprisingly, 2-25(N2A)GBP had slight plasmatocyte-spreading activity, whereas 2-25GBP lost its activity. Finally, substituted mutant, F3AGBP, had neither plasmatocyte-spreading activity nor antagonistic activity. These results demonstrate the function of each N-terminal residue in the interaction between GBP and its receptor in plasmatocytes.
AB - GBP, a small insect cytokine isolated from lepidopterans, has a variety of functions. We constructed a series of mutants focusing on the unstructured N-terminal residues of GBP by acetylation, deletion, and elongation in order to investigate the interaction between GBP and its receptor in plasmatocytes. The 1H NMR spectra showed no significant changes in the tertiary structures of these peptides, which indicated that all the mutants maintained their core β-sheet structures. The deletion and acetylated mutants, 2-25GBP, Ac2-25GBP, and AcGBP, lost their activity. 2-25GBP was the strongest antagonist, while Ac2-25GBP and AcGBP were moderate. In contrast, the elongated mutants, (-1R)GBP, (-1A)GBP, and (-2G,-1R)GBP maintained their plasmatocyte-spreading activity. These results demonstrate the importance of the GBP N-terminal charged amine and length of N-terminal GBP-peptide backbone for plasmatocyte-spreading activity. Next, we analyzed other mutant peptides, 1-25(N2A)GBP and 2-25(N2A)GBP, focusing on Asn2. Surprisingly, 2-25(N2A)GBP had slight plasmatocyte-spreading activity, whereas 2-25GBP lost its activity. Finally, substituted mutant, F3AGBP, had neither plasmatocyte-spreading activity nor antagonistic activity. These results demonstrate the function of each N-terminal residue in the interaction between GBP and its receptor in plasmatocytes.
KW - Antagonist
KW - EGF
KW - GBP
KW - Growth-blocking peptide
KW - Insect cytokine
KW - NMR
UR - http://www.scopus.com/inward/record.url?scp=33746584804&partnerID=8YFLogxK
U2 - 10.2174/092986606777841172
DO - 10.2174/092986606777841172
M3 - 学術論文
C2 - 17073728
AN - SCOPUS:33746584804
SN - 0929-8665
VL - 13
SP - 815
EP - 822
JO - Protein and Peptide Letters
JF - Protein and Peptide Letters
IS - 8
ER -