Cellobiose phosphorylase (EC 2.4.1.20, CBP) catalyzes the reversible phosphorolysis of cellobiose to α-D-glucose 1-phosphate (Glc1P) and d-glucose. Cys485, Tyr648, and Glu653 of CBP from Ruminococcus albus, situated at the +1 subsite, were mutated to modulate acceptor specificity. C485A, Y648F, and Y648V were active enough for analysis. Their acceptor specificities were compared with the wild t...

Fjelde et a!. (9) observed that D-glucosamine inhibited the growth of human epidermoid carcinoma cells in tissue culture, with concentration of 1 mg/mI causing death of the cells within 24 hr. The i.p. administration of divided doses of D-glucosamine or 2-deoxy-D-glucose inhibited the growth of Walker 256 carcinosarcoma in rats without significant toxicity to the host (1). Tumor growth resumed ...

Thymidine kinase activity in rat C6 glioma cells is inhibited by 50 to 70% after 4 hr incubation with 20 mM D-glucosamine. The inhibition is uncompetitive with respect to thymidine, reducing both the apparent Km and Vmax of the enzyme. The inhibition does not appear to be caused by the reversible combination of the enzyme with a cytoplasmic inhibitor, including D-glucosamine and its metabolites...

A partially purified enzyme (120-fold) from Leuconostoc mesenteroides catalyzed the reversible N-acetylation of d-glucosamine-6-phosphate. Coenzyme A was not required and inhibited the reaction rate. Neither d-glucosamine nor N-acetyl-d-glucosamine served as a substrate for the reversible reaction. The enzyme preparation retained 50% of its original activity after 5 min at 100 C. The K(m) for a...

D-Glucosamine is a useful medicament in various fields of medicine and dentistry. With respect to stability of the cell membrane, it has been reported that bradykinin-induced nociceptive responses are significantly suppressed by the direct application of D-glucosamine. Electroporation is usually used to effectively introduce foreign genes into tissue culture cells. Buffers for electroporation w...

The first enzyme of the pathway for uridine diphosphate N-acetyl-D-glucosamine (UDPAG) biosynthesis i.e. L-glutamine: D-fructose 6-P amidotransferase (E.C. 2.6.1.16) was purified 52-fold from human placenta using methanol fractionation and column chromatography on DEAE-Sephadex A-50. The enzyme showed optimal activity in a broad range of pH from 5.8 to 7.8 in both phosphate and cacodylate ...

Self-assembling heparin nanoparticles have attracted much attention as promising drug carriers for various drugs, genes and imaging agents. In the present investigation, we found that heparin nanoparticles are selective Toll-like receptor 4 (TLR-4) antagonists and have a much greater anti-inflammatory effect than native heparin. More specifically, we developed self-assembling nanoparticles comp...