Structural insights into polysaccharide recognition by Flavobacterium johnsoniae dextranase, a member of glycoside hydrolase family 31.

Glycoside hydrolase family (GH) 31 contains a large variety of enzymes, but the major members are enzymes that act on relatively small oligosaccharides such as α-glucosidase. Here, we determined the crystal structure of Flavobacterium johnsoniae dextranase (FjDex31A), an enzyme from F. johnsoniae that hydrolyzes a polysaccharide, dextran.

Evaluation of psychological stress in confined environments using salivary, skin, and facial image parameters.

Detecting the influence of psychological stress is particularly important in prolonged space missions. In this study, we determined potential markers of psychological stress in a confined environment. We examined 23 Japanese subjects staying for 2 weeks in a confined facility at Tsukuba Space Center, measuring salivary, skin, and facial image parameters.

Crystal structure of a β-fructofuranosidase with high transfructosylation activity from Aspergillus kawachii.

β-Fructofuranosidases belonging to glycoside hydrolase family (GH) 32 are enzymes that hydrolyze sucrose. Some GH32 enzymes also catalyze transfructosylation to produce fructooligosaccharides. We found that Aspergillus kawachii IFO 4308 β-fructofuranosidase (AkFFase) produces fructooligosaccharides, mainly 1-kestose, from sucrose.

A glycoside hydrolase family 31 dextranase with high transglucosylation activity from Flavobacterium johnsoniae.

Glycoside hydrolase family (GH) 31 enzymes exhibit various substrate specificities, although the majority of members are α-glucosidases. Here, we constructed a heterologous expression system of a GH31 enzyme, Fjoh_4430, from Flavobacterium johnsoniae NBRC 14942, using Escherichia coli, and characterized its enzymatic properties. The enzyme hydrolyzed dextran and pullulan to produce isomaltooligosaccharides and isopanose, respectively.