Premium
Purification and characterization of aconitase isoforms from etiolated pumpkin cotyledons
Author(s) -
Bellis Luigid,
Tsugeki Ryuji,
Alpi Amedeo,
Nishimura Mikio
Publication year - 1993
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1993.tb01363.x
Subject(s) - aconitase , isoelectric focusing , biochemistry , glyoxylate cycle , etiolation , gene isoform , chemistry , cucurbita , differential centrifugation , isoelectric point , size exclusion chromatography , biology , chromatography , enzyme , gene
Although aconitase (EC 4.2.1.3) is involved in the glyoxylate cycle, which is localized in glyoxysomes, we detected very low aconitase activity in glyoxysomal fractions after sucrose gradient centrifugation of extracts prepared from etiolated pumpkin ( Cucurbita sp.) colyledons. Two aconitase isoforms were purified to homogeneity, albeit in low yield, by hydrophobic interaction, hydroxylapatite and anion exchange chromatography. They were designated Aco I and Aco II; both were shown to be monomeric proteins of M 1 100 000 or 98 000 by gel filtration and SDS‐PAGE analysis, respectively; isoelectric points were 5.0 and 4.8, respectively. Kinetic studies revealed similarities between Aco I and Aco II. A third aconitase isoform (Aco III) was revealed but not purified to homogeneity.