A simple method for elucidating structures of galactomanno-oligosaccharides by sequential actions of .BETA.-mannosidase and .ALPHA.-galactosidase.

Abstract

Wereported in a previous paper1' that the hydrolysis of copra galactomannan by a /?-mannanase of Streptomyces sp. No. 17 produced three kinds of 1,4-/?-mannooligosaccharides (DP; 2-4) and four kinds of galactomanno-oligosaccharides (Ga^Man^Ga^Ma^, Gal2Man5, and Gal2Man6. See the abbreviations in Table I). All of the galactomanno-oligosaccharides were composed of a main-chain of (l ->4)-linked /?-D-mannoses (4-6 residues)to which single a-D-galactosyl stubs (1 or 2 residues)were directly attached through the 0-6 position. However, the precise location of the galactose stub was still unidentified, because we wereunable to find the position of the stub using physico-chemical procedures.This paper describes a simple method for elucidating structures ofgalactomanno-oligosaccharides using sequential actions /?-mannosidase and a-galactosidase, and also a structural study of four kinds of galactomanno-oligosaccharides.Galactomanno-oligosaccharides and 1,4-P-manno-oligosaccharides. Galactomanno-oligosaccharides (Gal1 Man4, Ga^Mang, Gal2Man5, and Gal2Man6) were prepared by the method described in a previous paper,1} from a hydrolysate of copra galactomannan (Gal : Man=1 : 14) by the /?-mannanase IV2) of Streptomyces sp. No. 17.Manno-oligosaccharides were also prepared by the method described in a previous paper.3)Enzymes. a-Galactosidase (EC 3.2.

BIOCATALYTIC ACTIVITY OF RECOMBINANT HUMAN Β-Mannosidase IMMOBILIZED ONTO MAGNETIC NANOPARTICLES FOR BIOPROCESS

“…b-MANB purified from Aspergillus niger was used to study the structure of galactomanno-oligosaccharide isolated from copra galacto-mannan, but the main catalytic domain of the enzyme is not discussed. [37] The magnetic nanoparticles are not only being used as the carrier for immobilization of enzyme(s) for saccharification, recycling, and continuous flow in mini bioreactors but also for carrying many fluorescent markers for magnetic resonance imaging and guided drug delivery for gastric cancer [14] and prostrate cancer. [15] The photodynamic therapy is also a valuable therapeutic tool to treat the tumor and cancer because it is nontoxic, noninvasive, and biocompatible for therapy.…”

Substrate Specificities ofα-Galactosidases from Yeasts

“…18 ) GaPMan 3 was prepared from GaPMan 4 by enzymatic hydrolysis with A. niger p-mannosidase. 19 ) The enzyme solution (500,ul, containing 0.6 units of a-galactosidas,~ activity) was added to 500,u1 of 1 % substrates (Gal 3 Man 3 or GaPMan 4 ) in McIlvaine buffer (pH 4.5), and then the mixture was incubated at 40°C. A small portion of the reaction mixture (100 ,ul) was withdrawn at 0.5,1,2,4, and 12h.…”