• MeSH
• Alcohols toxicity   MeSH
• Hydroxylation MeSH
• Microsomes, Liver drug effects   MeSH
• Ascorbic Acid administration & dosage   pharmacology   adverse effects   MeSH
• Guinea Pigs MeSH
• Oxides MeSH
• Animals MeSH
• Check Tag
• Guinea Pigs MeSH
• Animals MeSH

• MeSH
• Humans MeSH
• Ocular Physiological Phenomena MeSH
• Eye MeSH
• Retina anatomy & histology   physiology   MeSH
• Check Tag
• Humans MeSH

• MeSH
• Thoracic Vertebrae MeSH
• Spinal Cord physiology   MeSH
• Scoliosis etiology   pathology   MeSH
• Spinal Curvatures MeSH
• Publication type
• Review MeSH

x

x

• MeSH
• Running * standards   MeSH
• Track and Field MeSH
• Humans MeSH
• Reaction Time physiology   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH

• MeSH
• Aldosterone pharmacology   MeSH
• Dehydration physiopathology   MeSH
• Potassium urine   MeSH
• Infant MeSH
• Kidney physiopathology   MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Osmolar Concentration MeSH
• Sodium urine   MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Infant, Newborn MeSH

• MeSH
• Algorithms MeSH
• Adaptation, Biological MeSH
• Models, Biological MeSH
• Bone and Bones MeSH
• Periosteum MeSH
• Osteoblasts MeSH
• Bone Development MeSH

• Publication type
• Meeting Abstract MeSH

Fungal β-N-acetylhexosaminidases, though hydrolytic enzymes in vivo, are useful tools in the preparation of oligosaccharides of biological interest. The β-N-acetylhexosaminidase from Talaromyces flavus is remarkable in terms of its synthetic potential, broad substrate specificity, and tolerance to substrate modifications. It can be heterologously produced in Pichia pastoris in a high yield. The mutation of the Tyr470 residue to histidine greatly enhances its transglycosylation capability. The aim of this work was to identify the structural requirements of this model β-N-acetylhexosaminidase for its transglycosylation acceptors and formulate a structure-activity relationship study. Enzymatic reactions were performed using an activated glycosyl donor, 4-nitrophenyl N-acetyl-β-d-glucosaminide or 4-nitrophenyl N-acetyl-β-d-galactosaminide, and a panel of glycosyl acceptors of varying structural features (N-acetylglucosamine, glucose, N-acetylgalactosamine, galactose, N-acetylmuramic acid, and glucuronic acid). The transglycosylation products were isolated and structurally characterized. The C-2 N-acetamido group in the acceptor molecule was found to be essential for recognition by the enzyme. The presence of the C-2 hydroxyl moiety strongly hindered the normal course of transglycosylation, yielding unique non-reducing disaccharides in a low yield. Moreover, whereas the gluco-configuration at C-4 steered the glycosylation into the β(1-4) position, the galacto-acceptor afforded a β(1-6) glycosidic linkage. The Y470H mutant enzyme was tested with acceptors based on β-glycosides of uronic acid and N-acetylmuramic acid. With the latter acceptor, we were able to isolate and characterize one glycosylation product in a low yield. To our knowledge, this is the first example of enzymatic glycosylation of an N-acetylmuramic acid derivative. In order to explain these findings and predict enzyme behavior, a modeling study was accomplished that correlated with the acquired experimental data.

• MeSH
• beta-N-Acetylhexosaminidases chemistry   metabolism   MeSH
• Glycosides metabolism   MeSH
• Glycosylation MeSH
• Kinetics MeSH
• Protein Conformation MeSH
• Models, Molecular MeSH
• Oligosaccharides metabolism   MeSH
• Substrate Specificity MeSH
• Talaromyces enzymology   MeSH
• Structure-Activity Relationship MeSH
• Publication type
• Journal Article MeSH

• MeSH
• B-Lymphocytes immunology   MeSH
• Nematoda immunology   MeSH
• Immunization MeSH
• Mice MeSH
• Nematode Infections immunology   MeSH
• T-Lymphocytes immunology   MeSH
• Check Tag
• Mice MeSH
• Publication type
• Comparative Study MeSH