Osmotin from Calotropis procera latex: new insights into structure and antifungal properties.

Autor:	de Freitas CD; Departamento de Biologia, Universidade Federal do Piauí, Bairro Melladão, Floriano-Piauí, Brazil. cleversondiniz@hotmail.com, Lopes JL, Beltramini LM, de Oliveira RS, Oliveira JT, Ramos MV
Jazyk:	angličtina
Zdroj:	Biochimica et biophysica acta [Biochim Biophys Acta] 2011 Oct; Vol. 1808 (10), pp. 2501-7. Date of Electronic Publication: 2011 Jul 23.
DOI:	10.1016/j.bbamem.2011.07.014
Abstrakt:	This study aimed at investigating the structural properties and mechanisms of the antifungal action of CpOsm, a purified osmotin from Calotropis procera latex. Fluorescence and CD assays revealed that the CpOsm structure is highly stable, regardless of pH levels. Accordingly, CpOsm inhibited the spore germination of Fusarium solani in all pH ranges tested. The content of the secondary structure of CpOsm was estimated as follows: α-helix (20%), β-sheet (33%), turned (19%) and unordered (28%), RMSD 1%. CpOsm was stable at up to 75°C, and thermal denaturation (T(m)) was calculated to be 77.8°C. This osmotin interacted with the negatively charged large unilamellar vesicles (LUVs) of 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-rac-1-glycerol (POPG), inducing vesicle permeabilization by the leakage of calcein. CpOsm induced the membrane permeabilization of spores and hyphae from Fusarium solani, allowing for propidium iodide uptake. These results show that CpOsm is a stable protein, and its antifungal activity involves membrane permeabilization, as property reported earlier for other osmotins and thaumatin-like proteins. (Copyright © 2011 Elsevier B.V. All rights reserved.)
Databáze:	MEDLINE
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