of the surfaces z, with the property that a curve y9 intersects a surface yj once or zero times, modulo T, according as i is equal to or different from j. In other words, the intersection of y9 with yj is determined by the coefficient of ysyj in the bilinear form ytyj (mod x) Let 7rt' denote the number of times, modulo r, that a curve y9 cuts the surface zj bounded by y. The numbers 7r-' are th...

A novel protein adjuvant double-mutant Escherichia coli heat-labile toxin, LT (R192G/L211A) or dmLT, is in preclinical and early clinical development with various vaccine candidates. Structural characterization and formulation development of dmLT will play a key role in its successful process development, scale-up/transfer, and commercial manufacturing. This work describes extensive analytical ...

Paternal transmission of the bithorax-complex (BX-C) rearrangement, inversion Uab1, causes a specific dominant gain of function phenotype in most abdominal segments. This represents a case of paternal imprinting since the mutant phenotype will occur only if inversion Uab1 is paternally transmitted. The transformations in males are toward genital arch tissue. For females the transformations are ...

Introduction Verotoxin (VT) was first reported by Konowalchuk et al. in 1977. Although VT-producing E. coli strains belong to several different serotypes, 0157:H7 is the dominant serotype isolated from patients suffering from food poisoning. The infection frequently develops into hemorrhagic colitis. Furthermore, about 10% of these cases develop into the haemolytic uremic syndrome, which is the...

Cholera toxin (CTx) is an AB5 cytotonic protein that has medical relevance in cholera and as a novel mucosal adjuvant. Here, we report an analysis of the noncovalent homopentameric complex of CTx B chain (CTx B5) using electrospray ionization triple quadrupole mass spectrometry and tandem mass spectrometry and the analysis of the noncovalent hexameric holotoxin usingelectrospray ionization time...

The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB5 enterotoxin (choleragen). We have independently solved and refined the three-dimensional structure of choleragen at 2.5 A resolution. The structure of the crystalline toxin closely resembles that described for the heat-labile enterotoxin from Escherichia coli (LT) with which it shares 80% ...

Shiga toxin producing Escherichia coli O157:H7 (STEC) is one of the leading causes of food-poisoning around the world. Some STEC strains produce Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2) or variants of either toxin, which are critical for the development of hemorrhagic colitis (HC) or hemolytic uremic syndrome (HUS). Currently, there are no therapeutic treatments for HC or HUS. E. coli O...