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Abstract

From 100 g sunflower seeds, 1.2 mg purified alpha-galactosidase was obtained with an overall yield of 51%. The alpha-galactosidase acted on both terminal alpha-galactosyl residues and side-chain alpha-galactosyl residues of the galactomanno-oligosaccharides and galactomannans. The cDNA coding for sunflower alpha-galactosidase was cloned and the deduced amino acid sequence revealed that the mature enzyme consisted of 363 amino acid residues with a molecular weight of 40,263. Seven cysteine residues were found but no putative N-glycosylation sites were present in the sequence. The deduced amino acid sequences of mature enzyme and alpha-galactosidases from coffee, guar and Mortierella vinacea alpha-galactosidase II showed over 81%, 77%, and 47% homology, respectively. These enzymes are classified into the third group in which the enzyme has no insertion sequence and a broad specificity on galactomanno-oligosaccharides compared to the other groups.

Classification, Substrate Specificity and Application of α-Galactosidases

“…α-galactosidases (α-Gals, α-D-galactoside galactohydrolase), or melibiases [EC 3.2.1.22], are glycosidases that cleave, with the optical configuration retained, the terminal nonr educing α-Dgalactose residues from α-D-galactosides, including galactose oligosaccharides, galactomannans, glycoprotein and glycolipids [4].…”

“…On the other hand, Aspergillus niger 5-16α-Gal [18] and Penicillium purpurogenum α-Gal [19] show a preference for the G 3 M 4 having an αgalactosyl residue attached to the O-6 position of the third mannose from the reducing end of β-1,4mannotetraose. The Mortierella vinaceaα-Gal II [20], sunflower α-Gal [4] and acidic rice α-Gals [5] acts on both substrates and galactomannans. Since G 3 M 3 and G 3 M 4 were difficult to synthesize, the galactomanno-oligosaccharides specificities of α-Gals also could be investigated by using GM 2 (6 1 -α-D-galactosyl mannobiose), GM 3 (6 1 -α-D-galactosyl mannotriose) and GGM 5 (6 3 , 6 4 -di-α-D-galactosyl mannopentaose) [5].…”

“…The Mortierella vinaceaα-Gal II [20], sunflower α-Gal [4] and acidic rice α-Gals [5] acts on both substrates and galactomannans. Since G 3 M 3 and G 3 M 4 were difficult to synthesize, the galactomanno-oligosaccharides specificities of α-Gals also could be investigated by using GM 2 (6 1 -α-D-galactosyl mannobiose), GM 3 (6 1 -α-D-galactosyl mannotriose) and GGM 5 (6 3 , 6 4 -di-α-D-galactosyl mannopentaose) [5]. GM 2 and GM 3 are similar in structure to G 3 M 3 , which has a terminalα-galactosyl residue, and GGM 5 is similar to G 3 M 4 , which has side-chain α-galactosyl residues.…”

Reconstruction of mandibular defects with autogenous bone and decellularized bovine bone grafts with freeze-dried bone marrow stem cell paracrine factors

“…Thermal cycling conditions were as follows: 15 min of denaturation at 95°C, followed by 40 cycles of denaturation for 15 sec at 95°C, annealing for 30 sec at 60°C and elongation for 20 sec at 72°C. The 18S rRNA was used as an internal control for gene expression normalization, which is considered to be the most reliable reference gene for normalization of qPCR data (28). …”

Optimization of Saccharomyces cerevisiae α-galactosidase production and application in the degradation of raffinose family oligosaccharides

“…However, according to their specificity on synthetic galactomannan-oligosaccharides, α-Gals can be classified into three groups depending on whether they allow the terminal, internal or both galactose to be released from previously mentioned substrates [28]. The use of this type of synthetic substrates helps to determine the exact cleavage position of the α-1,6-glycosidic bond between a D-galactosyl residue and a d -mannose residue of the linear chain of β-1,4- d -mannose of galactomannan, but the difficulty in obtaining them means that few works report such data [29–31].…”