Hydrolysis of soy isoflavone glycosides by recombinant beta-glucosidase from hyperthermophile Thermotoga maritima.
A recombinant Thermotoga maritima beta-glucosidase A (BglA) was purified to homogeneity for performing enzymatic hydrolysis of isoflavone glycosides from soy flour. The kinetic properties K(m), k(cat), and k(cat)/K(m) of BglA towards isoflavone glycosides, determined using high-performance liquid chromatography, confirmed the higher efficiency of BglA in hydrolyzing malonylglycosides than non-conjugated glycosides (daidzin and genistin). During hydrolysis of soy flour by BglA at 80 degrees C, the isoflavone glycosides (soluble form) were extracted from soy flour (solid state) into the solution (liquid state) in thermal condition and converted to their aglycones (insoluble form), which mostly existed in the pellet to be separated from BglA in the reaction solution. The enzymatic hydrolysis in one-step and two-step approaches yielded 0.38 and 0.35 mg genistein and daidzein per gram of soy flour, respectively. The optimum conditions for conversion of isoflavone aglycones were 100 U per gram of soy flour, substrate concentration 25% (w/v), and incubation time 3 h for 80 degrees C.
Xue
Yemin
Y
Nanjing Engineering and Technology Research Center for Microbiology, Jiangsu Key Laboratory for Biodiversity and Biotechnology, Nanjing Normal University, Nanjing, People's Republic of China. xueyemin@njnu.edu.cn
Yu
Jinjin
J
Song
Xiangfei
X
D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006358:Hot Temperature; D006868:Hydrolysis; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D015394:Molecular Structure; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013025:Glycine max / Q000737:chemistry; D020124:Thermotoga maritima / Q000201:enzymology* / Q000235:genetics; D013997:Time Factors; D001617:beta-Glucosidase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D006027:Glycosides; D007529:Isoflavones; D011994:Recombinant Proteins; D001617:beta-Glucosidase
J Agric Food Chem. 2006 Oct 4;54(20):7495-502
17002413
Anal Biochem. 1976 May 7;72:248-54
942051
J Nutr Biochem. 2005 Apr;16(4):205-12
15808324
J Agric Food Chem. 2007 Mar 21;55(6):2407-12
17311399
Appl Microbiol Biotechnol. 2008 May;79(1):51-60
18340445
Am J Clin Nutr. 2000 Jun;71(6 Suppl):1705S-7S; discussion 1708S-9S
10837323
J Biol Chem. 2006 Oct 6;281(40):30251-9
16891302
J Nutr. 2000 Jul;130(7):1695-9
10867038
J Biotechnol. 2000 Feb 17;77(2-3):275-86
10682286
Biotechnol Lett. 2004 Oct;26(19):1511-5
15604789
J Nutr. 1995 Sep;125(9):2307-15
7666247
Nutr Rev. 2003 Oct;61(10):346-51
14604267
Adv Exp Med Biol. 2004;546:121-65
15584372
J Agric Food Chem. 2003 Apr 9;51(8):2212-5
12670158
Am J Clin Nutr. 2002 Aug;76(2):447-53
12145021
J Nutr. 2005 May;135(5):1243-7
15867312
Appl Microbiol Biotechnol. 2006 Nov;73(2):314-20
16715232