Methods of Removing Polyethylene Glycol From Plasma Fractions

An Endoglycosidase from Grape Berry Skin of Cv. M. Alexandria Hydrolyzing Potentially Aromatic Disaccharide Glycosides

“…Among the detergents, at the concentration used in the extraction medium (1%), poly(ethylene glycol) (PEG) was found to be the most efficient. This detergent is usually employed for protein precipitation (Ingham and Busby, 1980) and increased endoglycosidase extraction 7.5-fold in comparison to the other nonionic detergent (Triton X-100; Table 1). With Tween 80, the endoglycosidase was not extracted; however this detergent has been used in the extraction of β-glucosidase from grape berries (Aryan et al, 1987;Biron et al, 1988;Lecas et al, 1991).…”

“…Before chromatographic purification steps, the assays were carried out to remove more PEG 4000 from the crude enzyme extract. It is well-known that the PEG can affect the protein separation performance in chromatographic media (Ingham and Busby, 1980). Glycosidase activities were thus eluted with the void volume of a gel filtration column (Ultrogel AcA 44), when we used a grape crude enzyme extract containing 1% PEG 4000.…”

“…Detergent removal from the crude enzyme extract was assayed by salt-induced phase separation, according to the described procedure (Busby and Ingham, 1980). Although this approach permitted quite good separation of PEG (in upper phase) and protein in biological liquids (Ingham and Busby, 1980), the results were not satisfactory with the crude grape enzyme extract. Glycosidase activities were almost equally distributed in the upper and lower phases, and the detergent was not sufficiently separated in both phases.…”