title: Superoxide, hydrogen peroxide, and the gelling of phloem sap from Cucurbita pepo.
abstract: The possible involvement of superoxide and hydrogen peroxide in the oxidative gelling of phloem exudate from Cucurbita pepo. was investigated. Neither superoxide dismutase (EC 1.15.1.1) nor catalase (EC 1.11.1.6) inhibited the reaction. Although catalase could not be detected in exudate, both peroxidase (EC. 1.11.1.7) and superoxide dismutase were present in reasonable amounts. Polyacrylamide gel electrophoresis revealed one major and one minor isozyme of superoxide dismutase, both of which were adjudged to contain copper and zinc as their prosthetic metals, on the basis of cyanide inhibition and molecular weight.
authors.affiliation: Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, OX1 3QR, Oxford, UK.
authors.forename: A R
authors.initials: AR
authors.lastname: McEuen
authors.forename: H A
authors.initials: HA
authors.lastname: Hill