The periplasmic nuclease of Vibrio vulnificus, Vvn, has been purified to homogeneity by a one step purification procedure using chromatography on a SP Sepharose column. The purified enzyme showed different mobilities on reducing and non-reducing SDS-PAGE, suggesting that disulfide bonds are involved in the maintenance of a stable tertiary conformation of the protein. Vvn randomly cleaved single and double stranded DNA and RNA, and possessed endonucleolytic activity. The enzyme exhibited an optimal activity between pH 8.0 and pH 10.0, and the optimal temperatures for the DNase and RNase activity were 40 oC ¡V 60 oC and 40 oC ¡V 50 oC, respectively. The enzymatic activity was inhibited by EDTA and EGTA, indicating that Vvn was a metalloenzyme. The DNase and RNase activity of Vvn had different requirements for divalent cations. Chemical modification studies on Vvn revealed the involvement of lysine, arginine, tryptophan and carboxylate residues in the catalytic activity of the enzyme. The extents of inactivation of the DNase and RNase activity of Vvn by modification of the carboxylate group with EDC were different. Substrate DNA and RNA protected the DNase and RNase activity of Vvn from inactivation by PLP, PGO, NBS and EDC which modified lysine, arginine, tryptophan and the carboxylate group. Mg2+ could not protect the DNase and RNase activity of Vvn against the inactivation by PLP and PGO. Whereas Mg2+ protection was observed in NBS- and EDC-mediated inactivation of the DNase but not the RNase activity of Vvn . From these results, it is postulate that there may be two distinct but overlapping active sites, for the DNase and RNase activity, respectively.

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Texte remanié de: Diss.--Fachbereich für Orientalistik--Universität Hamburg, 1998. / Bibliogr. p. [335]-356. Index.

Diss.--Evangelisch-theologische Fakultät--Tübingen--Eberhard-Karls-Universität, Wintersemester 1998/1999. / Résumés en anglais et en arabe. Bibliogr. p. 203-222. Index.

Texte remanié de: Diss.--Geschichts- und Kulturwissenschaft. N°: Freie Universität Berlin, 1999. / Textes en allemand, résumés en anglais et allemand, sommaire en grec. Notes bibliogr.

Thesis--Faculty of arts and sciences--University of Pittsburgh, 1999. / Bibliogr. p. 220-241.

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Texte remanié de: Thèse de doctorat--Préhistoire, archéologie, histoire et civilisation de l'Antiquité et du Moyen âge--Aix-Marseille 1, 2004. Titre de soutenance : La céramique grecque d'Ensérune. / Bibliogr. p. 549-563. Résumé en français, italien, catalan, espagnol, anglais, allemand.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.

Thesis (M.S. in environmental science)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 26, 2010). "School of Earth and Environmental Sciences." Includes bibliographical references (p. 48-51).