Phosphorus-31 nuclear magnetic resonance spectroscopy reveals two conformational forms of chloroacetol phosphate-bound triosephosphate isomerase.

Chloroacetol phosphate covalently reacts with Glu-165 in the catalytic center of triosephosphate isomerase. Reaction of the enzyme with the substrate analogue results in two 31P resonances at 6.8 and 5.5 ppm. Dissociation with guanidinium chloride results in a single resonance at 4.5 ppm. Reassociation and redimerization of the triosephosphate isomerase-chloroacetol phosphate complex restores only the resonance at 5.5 ppm. The two 31P resonances appear to represent different conformations of the enzyme which are trapped upon reaction with the affinity label.

The effect of needle stimulation of acupuncture loci Tienshu (St-25) Chung-Wan (CV-12) on the immune response in sensitized mice against experimental cholera.

The effects of stimulation of acupuncture loci from Tien-Shu (St-25) piercing through Chung-Wan (CV-12) on the Leukocytes and immune response were assessed in mice (that is, the anatomical equivalent of these loci of human acupuncture points). The leukocyte count increased and reached its highest level two hours after needling, then restored to normal level 24 hours later both in normal mice and immunized mice. Statistical analysis showed no significant variation on the lymphocyte/total leukocyte ratio in normal mice or immunized mice before, during and after needling. The effects of acupuncture on the production of anti-Vibrio cholerae in serum of the immunized mice can not be found, but produced positive effects in small intestine both on production of SIgA and antagonism to cholera. Furthermore these enhanced effects were higher by needling after oral (p.o.) boosting than that before oral boosting.

Three monoclonal immunoglobulins, an IgG2(kappa), an IgM(kappa) and an IgM/A hybrid, in one patient. II. Sharing of common variable regions.

Amino acid sequencing and haemagglutination inhibition studies were performed on three monoclonal immunoglobulins (an IgG2, an IgM and an IgM/A hybrid) isolated from a patient afflicted with a multiple gammopathy. The results demonstrated that all three proteins have shared idiotypic determinant(s). Furthermore, the light chains of all three paraproteins have identical NH2-terminal amino-acid sequences at all positions determined thus far. Similarly, the NH2-terminal amino-acid sequence of the gamma 2 chains is identical to that of the mu chain. The evidence strongly suggests a common ancestral clonal origin for cells which produce these paraproteins and that identical variable region (VH and VL) genes were used by the ESM lymphocyte subclones in the biosynthesis of the respective IgM, IgG, and IgM/A hybrid molecules. The occurrence of a mu/alpha hybrid chain, which shares identical V regions with a mu and a gamma chain, is consistent with the concept that IgM-producing cells can develop directly into cells producing other classes of immunoglobulins via separate pathways during B-cell maturation.