TY - JOUR
T1 - Antifungal activity of rye (secale cereale) seed chitinases
T2 - The different binding manner of class i and class ii chitinases to the fungal cell walls
AU - Taira, Toki
AU - Ohnuma, Takayuki
AU - Yamagami, Takeshi
AU - Aso, Yoichi
AU - Ishiguro, Masatsune
AU - Ishihara, Masanobu
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2002
Y1 - 2002
N2 - The antifungal activities of rye seed chitinase-a (RSC-a, class I) and -c (RSC-c, class II) were studied in detail using two different bioassays with Trichoderma sp. as well as binding and degradation experiments with the cell walls prepared from its mycelia. RSC-a inhibited more strongly the re-extension of the hyphae, containing mainly mature cells, than RSC-c did. Upon incubation of the fungus with fluorescent chitinases, FITC- labeled RSC-a was found to be located in the hyphal tips, lateral walls, and septa, while FITC-labeled RSC-c was only in the hyphal tip. RSC-a had a greater affinity for the cell walls than RSC-c. RSC-a liberated a larger amount of reducing sugar from the cell walls than RSC-c did. These results inferred that RSC-a first binds to the lateral walls and septa, consisting of the mature cell walls, and degrades mature chitin fiber, while RSC-c binds only to the hyphal tip followed by degradation of only nascent chitin. As a result, RSC-a inhibited fungal growth more effectively than RSC-c. Furthermore, it was suggested that the chitin-binding domain in RSC-a assists the antifungal action of RSC-a by binding to the fungal hypha.
AB - The antifungal activities of rye seed chitinase-a (RSC-a, class I) and -c (RSC-c, class II) were studied in detail using two different bioassays with Trichoderma sp. as well as binding and degradation experiments with the cell walls prepared from its mycelia. RSC-a inhibited more strongly the re-extension of the hyphae, containing mainly mature cells, than RSC-c did. Upon incubation of the fungus with fluorescent chitinases, FITC- labeled RSC-a was found to be located in the hyphal tips, lateral walls, and septa, while FITC-labeled RSC-c was only in the hyphal tip. RSC-a had a greater affinity for the cell walls than RSC-c. RSC-a liberated a larger amount of reducing sugar from the cell walls than RSC-c did. These results inferred that RSC-a first binds to the lateral walls and septa, consisting of the mature cell walls, and degrades mature chitin fiber, while RSC-c binds only to the hyphal tip followed by degradation of only nascent chitin. As a result, RSC-a inhibited fungal growth more effectively than RSC-c. Furthermore, it was suggested that the chitin-binding domain in RSC-a assists the antifungal action of RSC-a by binding to the fungal hypha.
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U2 - 10.1271/bbb.66.970
DO - 10.1271/bbb.66.970
M3 - Article
C2 - 12092848
AN - SCOPUS:0036561178
VL - 66
SP - 970
EP - 977
JO - Bioscience, Biotechnology and Biochemistry
JF - Bioscience, Biotechnology and Biochemistry
SN - 0916-8451
IS - 5
ER -