Degradation pathway of plant complex-type N-glycans: identification and characterization of a key α1,3-fucosidase from glycoside hydrolase family 29.

Plant complex-type N-glycans are characterized by the presence of α1,3-linked fucose towards the proximal N-acetylglucosamine residue and ß1,2-linked xylose towards the ß-mannose residue. These glycans are ultimately degraded by the activity of several glycoside hydrolases. However, the degradation pathway of plant complex-type N-glycans has not been entirely elucidated because the gene encoding α1,3-fucosidase, a glycoside hydrolase acting on plant complex-type N-glycans, has not yet been identified, and its substrate specificity remains to be determined. In the present study, we found that AtFUC1 (an Arabidopsis GH29 α-fucosidase) is an α1,3-fucosidase acting on plant complex-type N-glycans. This fucosidase has been known to act on α1,4-fucoside linkage in the Lewis A epitope of plant complex-type N-glycans. We found that this glycoside hydrolase specifically acted on GlcNAcß1-4(Fucα1-3)GlcNAc, a degradation product of plant complex-type N-glycans, by sequential actions of vacuolar α-mannosidase, ß1,2-xylosidase, and endo-ß-mannosidase. The AtFUC1-deficient mutant showed no distinct phenotypic plant growth features; however, it accumulated GlcNAcß1-4(Fucα1-3)GlcNAc, a substrate of AtFUC1. These results showed that AtFUC1 is an α1,3-fucosidase acting on plant complex-type N-glycans and elucidated the degradation pathway of plant complex-type N-glycans.

Rapid nuclear import of short nucleic acids.

Exogenous short-chain nucleic acids undergo rapid import into the nucleus. Fluorescence-labeled dT1-13 DNA microinjected into the cytoplasm domain of a HeLa cell was rapidly imported into the nucleus domain within 1min. This is much more rapid than what has been observed for intracellular diffusion of small molecules. In contrast, import of longer nucleic acids with a length of over 30nt into the nucleus was suppressed.

Development of a Family Support Scale for Diet Therapy for Male Workers with type 2 diabetes.

AIM: Dietary self-care for patients with type 2 diabetes can be improved with family support. The purpose of this study was to develop a scale to assess family support for diet therapy for male workers with type 2 diabetes and to examine its reliability and validity. METHODS: In this cross-sectional study, we collected data from 110 Japanese male workers with type 2 diabetes. Data were analyzed using exploratory factor analysis, reliability testing, and validity testing. RESULTS: The resultant Family Support Scale for Diet Therapy for Male Workers (FSS-DMW) with type 2 diabetes consisted of 31 items and a six-factor structure. The six factors explained 72.9% of the variance, and Cronbach's alpha for the total scale was .964. The scale correlated as expected with the Social Support Scale for Chronic Illness and the dietary subscale of the Japanese version of the Summary of Diabetes Self-Care Activities Measure. CONCLUSION: The FSS-DMW is a reliable and valid measure which can be used to assess family support for diet therapy for male workers with type 2 diabetes and has the potential to be used as a clinical instrument for family guidance.

alpha-Mannosidase-catalyzed synthesis of a (1-->2)-alpha-D-rhamnodisaccharide derivative.

Enzymatic transglycosylation using p-nitrophenyl alpha-D-rhamnopyranoside as the glycosyl donor and 6equiv of ethyl 1-thio-alpha-D-rhamnopyranoside as the glycosyl acceptor yielded a D-rhamnooligosaccharide derivative. The reaction was catalyzed by jack bean alpha-mannosidase in a 1:1 (v/v) mixture of 0.1 M sodium citrate buffer (pH4.5)-MeCN at 25 degrees C. The enzyme exhibited high catalytic activity for the reaction, to afford in 32.1% isolated yield (based on donor substrate) ethyl alpha-D-rhamnopyranosyl-(1-->2)-1-thio-alpha-D-rhamnopyranoside, which is a derivative of the common oligosaccharide unit of the antigenic lipopolysaccharides from Pseudomonas.

Synthesis of nitrogen heterocycles via α-aminoalkyl radicals generated from α-silyl secondary amines under visible light irradiation.

We have succeeded in the visible light-mediated synthetic use of α-aminoalkyl radicals derived from α-silyl secondary amines toward addition to α,ß-unsaturated carbonyl compounds. The resulting γ-aminocarbonyl compounds are converted into γ-lactams and pyrroles in a one-pot process.