Isolation and polypeptide composition of 1,3-ß-glucan synthase from plasma membranes of Brassica oleracea

• The l,3‐ß‐glucan synthase (callose synthase, EC 2.4.1.34) was solubilized from cauliflower (Brassica oleracea L.) plasma membranes with digitonin, and partially purified by ion exchange chromatography and gel filtration [fast protein liquid chromatography (FPLC)] using 3‐[(cholamidopropyl)dimethylammonio]‐1‐propane‐sulfonate (CHAPS) in the elution buffers. These initial steps were necessary to obtain specific precipitation of the enzyme during product entrapment, the final purification step. Five polypeptides of 32, 35, 57, 65 and 66 kDa were highly enriched in the final preparation and are thus likely components of the callose synthase complex. The purified enzyme was activated by Ca2+, spermine and cellobiose in the same way as the enzyme in situ, indicating that no essential subunits were missing. The polyglucan produced by the purified enzyme contained mainly 1,3‐linked glucose.

Ämnesord

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

Brassica oleracea

callose synthase

cauliflower

1,3‐ß‐glucan synthase

plasma membranes

polypeptide composition

protein purification

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)