title: Euphorbia characias latex: micromorphology of rubber particles and rubber transferase activity.
abstract: We have recently characterized a natural rubber in the latex of Euphorbia characias. Following that study, we here investigated the rubber particles and rubber transferase in that Mediterranean shrub. Rubber particles, observed by scanning electron microscopy, are spherical in shape with diameter ranging from 0.02 to 1.2 μm. Washed rubber particles exhibit rubber transferase activity with a rate of radiolabeled [(14)C]IPP incorporation of 4.5 pmol min(-1)mg(-1). Denaturing electrophoresis profile of washed rubber particles reveals a single protein band of 37 kDa that is recognized in western blot analysis by antibodies raised against the synthetic peptide whose sequence, DVVIRTSGETRLSNF, is included in one of the five regions conserved among cis-prenyl chain elongation enzymes. The cDNA nucleotide sequence of E. characias rubber transferase (GenBank JX564541) and the deduced amino acid sequence appear to be highly homologous to the sequence of several plant cis-prenyltransferases.
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, CA, Italy.
authors.forename: Delia
authors.initials: D
authors.lastname: Spanò
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, CA, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pintus
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, CA, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Esposito
authors.affiliation: Department of Chemical and Geological Sciences, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, CA, Italy.
authors.forename: Danilo
authors.initials: D
authors.lastname: Loche
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, CA, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Floris
authors.affiliation: Department of Sciences of Life and Environment, University of Cagliari, Cittadella Universitaria, I-09042 Monserrato, CA, Italy. Electronic address: rmedda@unica.it.
authors.forename: Rosaria
authors.initials: R
authors.lastname: Medda
mesh_terms: D000595:Amino Acid Sequence; D018076:DNA, Complementary; D004122:Dimethylallyltranstransferase / Q000235:genetics / Q000378:metabolism; D028481:Euphorbia / Q000737:chemistry / Q000201:enzymology / Q000235:genetics; D007840:Latex / Q000737:chemistry / Q000378:metabolism; D008863:Microspheres; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D007840:Latex; D010940:Plant Proteins; D004122:Dimethylallyltranstransferase
keywords: Euphorbia characias; Latex; Rubber particles; Rubber transferase; cis-prenyltransferase