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Computational modeling and functional characterization of a GgChi: A class III chitinase from corms of Gladiolus grandiflorus
- Source :
- Kaohsiung Journal of Medical Sciences, Vol 34, Iss 12, Pp 673-683 (2018)
- Publication Year :
- 2018
- Publisher :
- Wiley, 2018.
-
Abstract
- The present study describes the predicted model and functional characterization of an endochitinase (30 kDa) from corms of Gladiolus grandiflorus. ESI-QTOF-MS generated peptide showed 96% sequence homology with family 18, Class III acidic endochitinase of Gladiolus gandavensis. Purified G. grandiflorus chitinase (GgChi) hydrolyzed 4-methylumbelliferyl β-d-N,N′,N′′-triacetylchitotriose substrate showing specific endochitinase activity. Since no structural details of GgChi were available in the Protein Data Bank (PDB), a homology model was predicted using the coordinate information of Crocus vernus chitinase (PDB ID: 3SIM). Ramachandran plot indicated 84.5% in most favored region, 14.8% in additional and 0.6% in generously allowed region while no residue in disallowed region. The predicted structure indicated a highly conserved (β/α)8 (TIM barrel) structure similar to the family 18, class III chitinases. The GgChi also showed sequence and structural homologies with other active chitinases. The GgChi (50 μg/disc) showed no antibacterial activity, but did provide mild growth inhibition of phytopathogenic fungus Fusarium oxysporum at a concentration of 500 μg/well Similarly, insect toxicity bioassays of GgChi (50 μg) against nymphs of Bemisia tabaci showed 14% reduction in adult emergence and 14% increase in mortality rate in comparison to control values. The GgChi (1.5 mg) protein showed significant reduction in a population of flour beetle (Tribolium castaneum) after 35 days, but lower reactivity against rice weevil (Sitophilus oryzae). The results of this study provide detai.led insight on functional characterization of a family 18 class III acidic plant endochitinase. Keywords: Gladiolus grandiflorus, Endochitinase, TIM barrel, Antibacterial, Antifungal
- Subjects :
- Medicine (General)
R5-920
Subjects
Details
- Language :
- English
- ISSN :
- 1607551X
- Volume :
- 34
- Issue :
- 12
- Database :
- Directory of Open Access Journals
- Journal :
- Kaohsiung Journal of Medical Sciences
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.9591c6335b484c9abacf955de4db21c6
- Document Type :
- article
- Full Text :
- https://doi.org/10.1016/j.kjms.2018.08.003