title: Purification and characterization of protein disulphide-isomerase from the unicellular green alga Chlamydomonas reinhardii. A 120 kDa dimer antigenically distinct from the vertebrate enzyme.
abstract: Protein disulphide-isomerase (PDI) has been isolated from the unicellular green alga Chlamydomonas reinhardii and purified by (NH4)2SO4 precipitation, gel filtration and DEAE-Sephacel, hydroxyapatite and f.p.l.c. chromatography. The active algal enzyme is a 120 kDa dimer with a subunit molecular mass of 60 kDa when determined by SDS/PAGE. Although similar in size to the previously isolated vertebrate PDIs, the algal enzyme is antigenically distinct, polyclonal antibodies against the algal PDI showing no cross-reactivity with the vertebrate enzyme on immunoblots, and vice versa. The anti-(algal PDI) antiserum did not inhibit algal PDI activity, and C. reinhardii PDI could be immobilized on anti-PDI-Protein A-Sepharose in active form. In contrast with the situation in vertebrates, where PDI functions as a subunit of prolyl 4-hydroxylase, the C. reinhardii PDI is not associated with the algal prolyl 4-hydroxylase.
authors.affiliation: Collagen Research Unit, University of Oulu, Finland.
authors.forename: D D
authors.initials: DD
authors.lastname: Kaska
authors.forename: K I
authors.initials: KI
authors.lastname: Kivirikko
authors.forename: R
authors.initials: R
authors.lastname: Myllylä
mesh_terms: D002696:Chlamydomonas / Q000201:enzymology*; D002845:Chromatography; D002851:Chromatography, High Pressure Liquid; D004355:Drug Stability; D006358:Hot Temperature; D007106:Immune Sera / Q000494:pharmacology; D015151:Immunoblotting; D007535:Isomerases / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D046911:Macromolecular Substances; D008970:Molecular Weight; D019704:Protein Disulfide-Isomerases
chemical_list: D007106:Immune Sera; D046911:Macromolecular Substances; D007535:Isomerases; D019704:Protein Disulfide-Isomerases