TY - JOUR
T1 - Structure and Enzymatic Properties of a Two-Domain Family GH19 Chitinase from Japanese Cedar (Cryptomeria japonica) Pollen
AU - Takashima, Tomoya
AU - Numata, Tomoyuki
AU - Taira, Toki
AU - Fukamizo, Tamo
AU - Ohnuma, Takayuki
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/6/6
Y1 - 2018/6/6
N2 - CJP-4 is an allergen found in pollen of the Japanese cedar Cryptomeria japonica. The protein is a two-domain family GH19 (class IV) Chitinase consisting of an N-terminal CBM18 domain and a GH19 catalytic domain. Here, we produced recombinant CJP-4 and CBM18-truncated CJP-4 (CJP-4-Cat) proteins. In addition to solving the crystal structure of CJP-4-Cat by X-ray crystallography, we analyzed the ability of both proteins to hydrolyze chitin oligosaccharides, (GlcNAc)n, polysaccharide substrates, glycol chitin, and β-chitin nanofiber and examined their inhibitory activity toward fungal growth. Truncation of the CBM18 domain did not significantly affect the mode of (GlcNAc)n hydrolysis. However, significant effects were observed when we used the polysaccharide substrates. The activity of CJP-4 toward the soluble substrate, glycol chitin, was lower than that of CJP-4-Cat. In contrast, CJP-4 exhibited higher activity toward β-chitin nanofiber, an insoluble substrate, than did CJP-4-Cat. Fungal growth was strongly inhibited by CJP-4 but not by CJP-4-Cat. These results indicate that the CBM18 domain assists the hydrolysis of insoluble substrate and the antifungal action of CJP-4-Cat by binding to chitin. CJP-4-Cat was found to have only two loops (loops I and III), as reported for ChiA, an allergenic class IV Chitinase from maize.
AB - CJP-4 is an allergen found in pollen of the Japanese cedar Cryptomeria japonica. The protein is a two-domain family GH19 (class IV) Chitinase consisting of an N-terminal CBM18 domain and a GH19 catalytic domain. Here, we produced recombinant CJP-4 and CBM18-truncated CJP-4 (CJP-4-Cat) proteins. In addition to solving the crystal structure of CJP-4-Cat by X-ray crystallography, we analyzed the ability of both proteins to hydrolyze chitin oligosaccharides, (GlcNAc)n, polysaccharide substrates, glycol chitin, and β-chitin nanofiber and examined their inhibitory activity toward fungal growth. Truncation of the CBM18 domain did not significantly affect the mode of (GlcNAc)n hydrolysis. However, significant effects were observed when we used the polysaccharide substrates. The activity of CJP-4 toward the soluble substrate, glycol chitin, was lower than that of CJP-4-Cat. In contrast, CJP-4 exhibited higher activity toward β-chitin nanofiber, an insoluble substrate, than did CJP-4-Cat. Fungal growth was strongly inhibited by CJP-4 but not by CJP-4-Cat. These results indicate that the CBM18 domain assists the hydrolysis of insoluble substrate and the antifungal action of CJP-4-Cat by binding to chitin. CJP-4-Cat was found to have only two loops (loops I and III), as reported for ChiA, an allergenic class IV Chitinase from maize.
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U2 - 10.1021/acs.jafc.8b01140
DO - 10.1021/acs.jafc.8b01140
M3 - Article
C2 - 29756783
AN - SCOPUS:85047102810
VL - 66
SP - 5699
EP - 5706
JO - Journal of Agricultural and Food Chemistry
JF - Journal of Agricultural and Food Chemistry
SN - 0021-8561
IS - 22
ER -