ISSN:
0006-3592
Keywords:
α-galactosidase
;
soybeans
;
lectin
;
scaleup
;
chromatography
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Soybeans (Glycine max) contain an α-galactosidase that makes up a small fraction of the total protein of the seed. The properties of this enzyme are of interest because of its potential to convert the galactooligosaccharides, stachyose and raffinose, in soybean meal to sugars digestible in the human gastro intestinal tract and thereby increase potential uses of this vegetable protein source in human and animal foods. Study of this enzyme required the isolation of milligram quantities of electrophoretically pure protein from ground soybeans and therefore, scaleup of laboratory procedures by a factor of 300 times. Large scale acid precipitation, ammonium sulfate precipitation, and centrifugal recovery of the precipitated protein allowed α-galactosidase to be isolated from 45.5 kg soybean meal containing 17.1 kg protein, to obtain an enzyme extract with a specific activity of 90 to 100. A novel combination of strong anion exchange and cation exchange chromatography followed by Concanavalin-A affinity chromatography with a methyl α-D mannoside gradient gave α-galactosidase with an average specific activity of 56,000. Ion exchange chromatography preceding Concanavalin-A affinity chromatography allowed elimination of a relatively costly melibiose affinity chromatography step (which followed the Concanavalin-A column In the laboratory procedure) thereby making scaleup practical.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bit.260370409
