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ACID INVERTASES FROM WHITE YAM, ( DIOSCOREA ROTUNDATA ) TUBER: PURIFICATION AND CHARACTERIZATION OF TWO ISOENZYMES
Author(s) -
NOK ANDREW J.,
IGWE UKOHA A.,
TITUS IBIEM.
Publication year - 1992
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.1992.tb00437.x
Subject(s) - invertase , dioscorea rotundata , raffinose , dioscorea , sucrose , lactose , maltose , enzyme , glycoside hydrolase , biology , dioscoreaceae , isozyme , biochemistry , chemistry , botany , food science , medicine , alternative medicine , pathology
White yam invertase (E.C. 3.2.1.26) was extracted from Dioscorea rotundate tuber and purified 30 fold. The enzyme consists of two molecular forms, termed invertases I and II, with average molecular weights of 263,000 ± 1000 and 230,000 ± 2000, respectively. Both enzymes had a temperature optima of 40C, and pH optima of 4.7 and 6.0 for invertases I and II, respectively. The K m values for invertases I and II were 4.65 m M and 9.25 m M, respectively, with sucrose as substrate. The enzymes were less specific for maltose, lactose, raffinose, melezitose, planteose, and lychnose than for sucrose.