The location of regions in the primary structure of UDP-galactose:N-acetylglucosamine beta 4-galactosyl-transferase (GT) that are involved in binding UDP-galactose has been investigated by differential chemical modification with two different reagents in the presence and absence of UDP-galactose. Treatment with periodate-cleaved UDP and NaCNBH3 resulted in a loss of 80% of GT activity, which wa...

The incorporation of glucose-% and 35S-labeled inorganic sulfate into heparin has been demonstrated in tissue slices of mouse mast cell tumors (1, 2). In addition, incorporation of 35S-labeled inorganic sulfate has been demonstrated in cell-free systems of DBA mouse mast cell tumors with 3’-phosphoadenosine 5’-phosphosulfate as a probable intermediate (3-6). However, the enzymatic reactions lea...

Small cell lung cancer (SCLC) occurs as two neuroendocrine subtypes, SCLC-C (classic) and SCLC-V (variant). One reported difference is elevated levels of diphosphodiesters (DPDE) in the more differentiated SCLC-C subtype. DPDE have been identified as primarily UDP-JVacetylhexosamines (UDP-NAH) in a variety of tumors, and changes in DPDE levels have been observed during experiments designed to i...

Clostridium perfringens TpeL belongs to a family of large clostridial cytotoxins that encompasses Clostridium difficile toxin A (TcdA) and B (TcdB) and Clostridium sordellii lethal toxin (TcsL). We report here the identification of the TpeL-catalyzed modification of small GTPases. A recombinant protein (TpeL1-525) derived from the TpeL N-terminal catalytic domain in the presence of streptolysin...

Previously we reported that stable transfection of human UDP-glucose pyrophosphorylase (hUGP2) rescued galactose-1-phosphate uridyltransferase (GALT)-deficient yeast from "galactose toxicity." Here we test in human cell lines the hypothesis that galactose toxicity was caused by excess accumulation of galactose-1-phosphate (Gal-1-P), inhibition of hUGP2, and UDP-hexose deficiency. We found that ...

This document updates the IPv6 specification (RFC 2460) to improve performance when a tunnel protocol uses UDP with IPv6 to tunnel packets. The performance improvement is obtained by relaxing the IPv6 UDP checksum requirement for tunnel protocols whose header information is protected on the "inner" packet being carried. Relaxing this requirement removes the overhead associated with the computat...

This paper develops an unsupervised discriminant projection (UDP) technique for feature extraction. UDP takes the local and non-local information into account, seeking to find a projection that maximizes the non-local scatter and minimizes the local scatter simultaneously. This characteristic makes UDP more intuitive and more powerful than the up-to-date method ocality preserving projection (LP...