Low-molecular-weight GTP-binding proteins serving as ADP-ribosylation substrate for ADP-ribosyltransferase from Clostridium botulinum and their relation to phosphoinositides metabolism in thymocytes

ADP-ribosyltransferase from Clostridium botulinum type C strain was found to induce an increase of inositol phosphates (IPs) formation in murine thymocytes membranes. Incubation of electropermeabilized murine thymocytes with the enzyme also caused an increase of IPs formation in the cells. This increase of IPs formation in the enzyme-treated membranes and electropermeabilized cells was dependent on the amount of both NAD and the enzyme, suggesting that the stimulation of phosphoinositide-specific phospholipase C (PLC) was related to ADP-ribosylation of membrane proteins by the enzyme. On the other hand, in calf and murine thymocytes two proteins with the same molecular weight of 21,000 were found to be ADP-ribosylated by the botulinum ADP-ribosyltransferase. A minor ADP-ribosylation substrate was shown by two-dimensional polyacrylamide gel electrophoresis to be G21k, a low-molecular-weight GTP-binding protein (G protein) suggested previously by us to be involved in PLC regulation [Wang, P. et al. (1987) J. Biochem. 102, 1275-1287; (1988) 103, 137-142; and (1989) 105, 461-466], and the other major ADP-ribosylation substrate was identified as a rho A protein. Under the experimental conditions of the IPs formation study, ADP-ribosylation of both G21k and rho A proteins by botulinum ADP-ribosyltransferase in membranes and permeabilized cells was observed. These results suggest that botulinum ADP-ribosyltransferase-induced PLC stimulation in thymocytes is closely correlated with ADP-ribosylation of the low-molecular-weight G proteins.

The complete nucleotide sequence of the gene coding for botulinum type C1 toxin in the C-ST phage genome

Two DNA fragments, 3 kbp and 7.8kbp, which encode the type C1 botulinum neurotoxin gene, were obtained from toxigenic bacteriophage DNA by treatment with a restriction enzyme. They were cloned into the plasmid vectors for nucleotide sequence determination. The nucleotide sequence contained a single open reading frame coding for 1,291 amino acids corresponding to a polypeptide with a molecular weight of 149,000. The amino acid sequence of the C1 toxin has a few regions highly homologous with tetanus toxin.

Separation of toxic activity and ADP-ribosylation activity of botulinum neurotoxin D

Neurotoxin from Clostridium botulinum type D strain South African (neurotoxin D) has shown ADP-ribosylation activity as well as toxic activity (Matsuoka, I., Sakuma, H., Syuto, B., Moriishi, K., Kubo, S., and Kurihara, K. (1989) J. Biol. Chem. 264, 706-712). Separation of these activities from each other was attempted by means of gel filtration, hydroxylapatite column chromatography, or immunoaffinity chromatography. Approximately 90% of toxic activity was recovered in each chromatography. Although ADP-ribosylation activity was incompletely separated from neurotoxin D by gel filtration, it was separated by hydroxylapatite column chromatography. In immunoaffinity chromatography with a column of Sepharose 4B coupling antibodies against botulinum ADP-ribosyltransferase, no ADP-ribosylation activity was detected by autoradiography in the unabsorbed toxic fraction. These results indicate that neurotoxin D does not have ADP-ribosylation activity.

Epidermal growth factor accelerates the intestinal cessation of macromolecular transmission in the suckling rat

1. The effects of EGF administered subcutaneously on the intestinal cessation of macromolecular transmission and sucrase development were investigated in suckling rats and compared with those on hydrocortisone-treated pups. 2. In the EGF-treated pups, intestinal absorptive response of IgG was suppressed 50% whereas, the sucrase activity was not affected. In the hydrocortisone-treated pups, the absorptive response was inhibited completely, while sucrase activity was induced precociously. 3. The characteristics of intestinal cessation was morphologically observed at the jejunal epithelial cells in EGF and hydrocortisone-treated pups. 4. These results suggest that EGF affects the maturation of gastrointestinal function in a manner different from that of glucocorticoid hormones.

Chemiluminescence of neutrophils from patients with Behçet's disease and its correlation with an increased proportion of uncommon serotypes of Streptococcus sanguis in the oral flora

Zymosan-induced chemiluminescence was investigated in whole blood and in neutrophils: in both, the peak count was frequently elevated in Behçet's disease, and was significantly higher than in healthy controls; similarly the peak time was shorter. There were more uncommon serotypes of Streptococcus sanguis in the oral flora of patients with Behçet's disease. Common serotypes were present in the flora of healthy controls, but not in patients with the disease. The percentage of Strep. sanguis in the oral flora was significantly correlated with the level of chemiluminescence response. Thus infection with uncommon serotypes of Strep. sanguis may play a role in the aetiology of Behçet's disease.

Lactate dehydrogenase and creatine phosphokinase isoenzymes in tissues of laboratory animals

The lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) isoenzyme distributions in tissues of the ICR mouse, Wistar rat, guinea pig and golden hamster were analyzed by histoelectrophoresis. Tissues obtained were as follows: liver, pancreas, stomach, small intestine, heart, femoral muscle, uterus, kidney, spleen, lymph node, cerebrum, spinal cord and erythrocyte. Histoelectrophoresis was for the direct analysis of LDH and CPK isoenzymes in the tissues and had high practical value compared with previous tissue-extraction methods. In tissues of the mouse, guinea pig and golden hamster, LDH isoenzymes showed five bands. In the rat, LDH isoenzyme was separated into four fractions. CPK isoenzyme showed three bands; BB, MB and MM. In some tissues, the MM band was separated into two sub fractions.

Molecular diversity of neurotoxins from Clostridium botulinum type D strains

The molecular properties of Clostridium botulinum type D South African (D-SA) were compared with those of neurotoxins from type D strain 1873 (D-1873) and type C strains Stockholm and 6813. D-SA toxin, purified 610-fold from the culture supernatant in an overall yield of 30%, consisted of an intact peptide chain with a molecular weight of 140,000. Limited proteolysis of the toxin by trypsin formed a dichain structure consisting of a light chain (Mr, 50,000) and a heavy chain (Mr, 90,000) linked by a disulfide bond(s) and enhanced the lethal activity about fourfold. Antibodies against the D-SA toxin light chain reacted with D-1873 toxin but not with C1 toxins. On the other hand, antibodies against the heavy chain of D-SA toxin cross-reacted with type C strain Stockholm, D-1873, and type C strain 6813 toxins in that order. Amino-terminal sequences of heavy and light chains of D-SA and D-1873 toxins were similar but not identical. These results indicate that within the type D strains, neurotoxins differ in molecular structure and antigenicity.

Lactate dehydrogenase isoenzyme patterns in bovine liver tissue

Liver lactate dehydrogenase (LDH) isoenzymes in normal and diseased cows were analyzed electrophoretically. This method (histoelectrophoresis) was improved for the direct analysis of tissue LDH isoenzymes. The mean values of LDH 1 through LDH 5 in the livers of normal cows were 31.7, 24.8, 27.3, 12.8, and 3.3%, respectively. In cases with hydropic degeneration of the liver, the patterns revealed increases of LDH 1 and LDH 2 as compared to normal cows. The patterns showed a decrease of LDH 1 and an increase of LDH 2 in fatty change of the liver. Congestion of the liver alone decreased LDH 1 and increased LDH 3, LDH 4 and LDH 5. Necrosis of the liver decreased LDH 1 and LDH 2, and increased LDH 3, LDH 4 and LDH 5. It was suggested that the functional hepatocellular damage due to anoxia might be a important factor of the change of liver LDH isoenzyme patterns. We have attempted to standardize the LDH isoenzyme patterns by using a computer under various conditions. In cases with hydropic lesions, the diagnostic sensitivity (DS) was 53% (28 of 53 cases) and the predictive value of positive tests (PVPT) was 100% (28 cases of 28 cases selected). In cases with congestive or necrotic lesions, DS was 41% (9 of 22 cases) and PVPT was 69% (9 cases of 13 cases selected).

Analysis of colostral proteins in calf serum by enzyme-linked immunosorbent assay

Enzyme-linked immunosorbent assay method was improved to monitor the concentrations of colostral proteins in the range of 10 to 10(3) ng/ml in calf serum. Colostral proteins were purified from fat-free colostrum, and antibodies against them were prepared from the rabbit anti-colostrum protein sera. Concentration of each protein was determined by enzyme-linked immunosorbent assay without interference by calf serum proteins in a mixture of colostrum and precolostral calf serum. Changes in the colostral protein concentrations in the sera of five postcolostral calves were monitored by enzyme-linked immunosorbent assay. After feeding colostrum to the neonatal calf, serum IgG concentration increased rapidly within 16 h to 8.1 to 36.8 mg/ml and gradually declined until 3 d to the steady levels, 4.7 to 23.6 mg/ml. The concentrations of casein and P2 (colostral small proteins, which were eluted at the second peak in Sephadex G-100 gel filtration) also increased more rapidly within 16 h to 9.6 to 264.0 micrograms/ml and 31.5 to 1600 micrograms/ml, respectively, and steeply decreased to near the detection limit on 3 d after feeding. These results indicate that enzyme-linked immunosorbent assay is useful to measure and monitor the absorbed colostral proteins and also to survey calves receiving and not receiving colostrum.

ADP-ribosylation of 24-26-kDa GTP-binding proteins localized in neuronal and non-neuronal cells by botulinum neurotoxin D

Clostridium botulinum D (strain South Africa) produces ADP-ribosyltransferase which modifies eukaryotic 24-26-kDa proteins. ADP-ribosyltransferase activity was associated with a neurotoxin of 150 kDa (Dsa toxin) as confirmed by the elution profile of Dsa toxin from high performance anion-exchange column. The 24-kDa substrate of Dsa toxin-catalyzed ADP-ribosylation was detected in several tissues examined including rat brain, heart, and liver; bovine adrenal medulla; sea urchin eggs; electric organs of electric fish; and cell lines of neural (N18, N1E115, NS20Y, NG108, PC12, and C6) and non-neural (3T3) origins, suggesting its ubiquitous localization in eukaryotic cells. On the other hand, the 26-kDa substrate was detected only in membrane fractions of neural tissues and neuronal cells, suggesting its specific localization in membrane of nerve terminals. ADP-ribosylation of both the 24-kDa substrate in PC12 membrane and the 24-26-kDa substrates in rat brain membrane was potentiated by either divalent cations or guanine nucleotides, whereas adenine nucleotides did not affect the ADP-ribosylation reaction. Trypsin digestion of the 24-kDa substrate in PC12 membrane and the 24-26-kDa substrates in rat brain membrane extract produced different tryptic fragments indicative of the structural difference between the 24- and 26-kDa substrates. Both the 24- and 26-kDa substrates were less sensitive to trypsin digestion before being ADP-ribosylated by Dsa toxin than after, suggesting the conformational alterations of the 24-26-kDa proteins induced by ADP-ribosylation. These results suggest that Dsa toxin modifies two distinct low molecular mass GTP-binding proteins by ADP-ribosylation to alter their putative function(s).

Binding of Clostridium botulinum type C neurotoxin to different neuroblastoma cell lines

Binding of type C neurotoxin (C1 toxin) from Clostridium botulinum (strain Stockholm) to neuroblastoma cell lines was studied by using biotinylated anti-toxin antibody and avidin-biotinylated peroxidase complex. The neurotoxin bound with high efficiency to mouse neuroblastoma (NS-20Y and NIE-115) cells and to hybridomas of rat glioblastoma and mouse neuroblastoma (NG108-C15) cells. The toxin bound little to human neuroblastoma, rat astrocytoma, and nonneural cell lines. Binding of the neurotoxin to NG108-C15 cells was inhibited by gangliosides (GT1b and GM1) and by monoclonal antibodies (CA-12 and C-9), although inhibition was not complete. Sequential preincubation of C1 toxin with GT1b and CA-12 caused complete inhibition. A Scatchard plot of binding of 125I-labeled C1 toxin to NG108-C15 cells showed a hyperbolic curve. Monoclonal antibody CA-12 but not C-9 neutralized the lethal activity of the toxin toward mice. Only C-9 clearly inhibited toxin binding to GT1b. These results suggest that NG108-C15 cells have at least two kinds of receptors for C1 toxin. From the results of binding tests with neuraminidase-, pronase-, and trypsin-treated NG108-C15 cells, the chemical nature of the high-affinity site was presumed to be a glycoprotein containing sialic acid. GT1b may have an important role in low-affinity sites.

Establishment of a monoclonal antibody recognizing an antigenic site common to Clostridium botulinum type B, C1, D, and E toxins and tetanus toxin

The partial amino acid sequence of the light-chain (Lc) component of Clostridium botulinum type C1 toxin was determined. The sequence was quite similar to those of the other types of botulinum and tetanus toxins. Nine monoclonal antibodies against botulinum type E toxin were established by immunizing BALB/c mice with type E toxoid or its Lc component. Six antibodies reacted with the heavy-chain component and three reacted with the Lc component of the toxin. One of the latter three antibodies reacted with botulinum type B, C1, and D toxins and tetanus toxin, as well as botulinum type E toxin. This antibody recognized the Lc components of these toxins, indicating that there exists one common antigenic determinant on the Lc regions of these toxins.

Biliary and pancreatic exocrine secretions via endogenous secretin by intestinal infusion of propionate and propionate analogues in piglets

1. The secretory responses of hepatic bile and exocrine pancreas by intraduodenal infusion of propionate (PA), 3Cl-PA, 2Cl-PA, 3Br-PA and 2Br-PA solutions were examined in anesthetized piglets. 2. Pancreatic juice and protein secretions were enhanced by infusion of PA and PA analogue solutions of pH 2.0 following increase of plasma secretin level but not pH 7.0. The order of response time was as follows: 3Br-PA greater than 2Cl-PA greater than 2Br-PA greater than 3Cl-PA greater than PA. 3. The response of bile flow depended on endogenous secretin and showed almost the same pattern as that of pancreatic juice secretion. 4. The results suggested that pancreatic exocrine secretion via endogenous secretin was not always dependent on the dissociation constant of weak acids.

Action of botulinum neurotoxin on acetylcholine release from rat brain synaptosomes: putative internalization of the toxin into synaptosomes

The action of botulinum neurotoxin type C1 on the release of acetylcholine from rat brain synaptosomes was studied by using anti-toxin heavy chain Fab and anti-toxin light chain Fab. The toxin was bound to synaptosomes at 0 degrees C for 10 min, in which [14C]acetylcholine had been accumulated previously. The toxin-binding synaptosomes were pre-incubated at 37 degrees C, and the release of acetylcholine was determined after the synaptosomes had been incubated in 25 mM KCl-incubation medium for 20 min at 37 degrees C. Inhibition of [14C]acetylcholine release from the synaptosomes was observed with increasing pre-incubation time and toxin concentration, and the maximum inhibition was seen after pre-incubation for at least 15 min, which was called the "lag time." The toxin-binding synaptosomes were reacted with anti-toxin heavy chain and anti-toxin light chain Fabs at 0 degrees C for 1.5 min before pre-incubation of the synaptosomes at 37 degrees C. Both Fabs reversed the acetylcholine release inhibition by the toxin. However, when the Fabs were added during the pre-incubation time at 37 degrees C, they showed less restoration with increasing pre-incubation time. The restoration was completely abolished if the Fabs were added to the synaptosomes after the first half of the "lag time." On the other hand, when 125I-labeled toxin-binding synaptosomes were reacted with the Fabs at 0 degrees C for 1.5 min before pre-incubation of the synaptosomes at 37 degrees C, anti-heavy chain Fab removed 125I-toxin from the synaptosomes, but anti-light chain Fab did not. However, if the Fabs were added to toxin-binding synaptosomes during the pre-incubation time at 37 degrees C, the Fabs could not remove 125I-toxin from the synaptosomes, and the synaptosomes retained more labeled toxin with increasing pre-incubation time. These results suggest that there are three distinct steps in the inhibition of acetylcholine release from synaptosomes by botulinum neurotoxin. The first is binding, which is reversible, temperature-independent, and mediated by the heavy chain of the toxin. The second is temperature-dependent internalization, that takes place in the first half of the "lag time," in which both the chains are internalized into synaptosomes. The third is the development of toxicity, which requires the latter half of the "lag time."

Binding and cytotoxic effects of Clostridium botulinum type A, C1 and E toxins in primary neuron cultures from foetal mouse brains

Binding of purified Clostridium botulinum type A, C1 and E toxins to cultured cells was studied by an immunocytochemical method. Type A and C1 toxins bound strongly to neuron cultures prepared from brains of foetal mice, but binding of type E toxin was weak. None of the toxin types bound to the feeder layer, composed of non-neuronal cells. The heavy-chain component of the type C1 toxin bound to neurons, but the light chain component did not. Type C1 toxin also bound only to cell lines of neuronal origin. When type C1 toxin [final concentration 4 x 10(2) LD50 (10 ng) per well] was added to primary neuron cultures in 96-well plates, degeneration of neuronal processes and rounding of neuronal somas were observed, but type A and E toxins did not produce such changes. The binding and cytotoxic activities of type C1 toxin were blocked by heat treatment (80 degrees C for 30 min) or by preincubation of the toxin with polyclonal anti-C1 IgG and some of the monoclonal antibodies which neutralized the toxin activity in mice. In the neuronal processes treated with C1 toxin, many degenerated mitochondria, membranous dense bodies and vesicles were observed by electron microscopy; these ultrastructural changes were similar to those of Wallerian degeneration in vivo.

Antitumor effect of adriamycin entrapped in liposomes conjugated with monoclonal antibody against tumor-associated antigen of bovine leukemia cells

Monoclonal antibody against tumor-associated antigen (TAA) expressed on bovine leukemia cells was conjugated to liposomes containing adriamycin (ADM), and the specificity and therapeutic effects of the conjugates were examined in vitro and in vivo using a TAA-positive bovine leukemia cell line as the target tumor. In vitro studies with the TAA-positive cell line clearly indicated that the antibody-conjugated liposomes containing ADM exerted selective effects on TAA-positive cells in the inhibition assay of 3H-thymidine incorporation. Three injections of liposomes containing ADM (4 mg/kg) into tumor-bearing nude mice significantly inhibited the tumor growth and the therapeutic effect of the antibody-conjugated liposomes was far greater than that of normal mouse IgG-conjugated liposomes as assessed in terms of tumor size.

Activation of Clostridium botulinum type E toxin purified by two different procedures

Clostridium botulinum type E toxin was purified from culture supernates and from cell extracts by two methods. The specific activity [2 X 10(4) mouse LD50 (mg protein)-1] of the toxin purified from cell extract under slightly acidic conditions was lower than that [3 X 10(5) LD50 (mg protein)-1] of the toxin purified from culture supernate under slightly alkaline conditions. Both toxin preparations were activated by trypsin treatment, but to different extents, the degree of activation of the toxin from cell extract being about 30-fold higher than that of the toxin from culture supernate. The two toxin preparations had the same electrophoretic mobility on SDS-polyacrylamide gels and antigenic specificity as revealed by agar gel double-immunodiffusion tests. The antigenic specificity of the two toxin preparations was unaltered by trypsin treatment. In SDS-polyacrylamide gel electrophoresis, a single band of Mr 144,000 was demonstrated before trypsin treatment and two bands of Mr 100,000 and 55,000 appeared after trypsin treatment. The two toxin preparations were labelled with 125I and chymotryptic peptide maps were obtained before and after trypsin treatment. The two toxin preparations without trypsin treatment demonstrated many differences in their peptide maps, but the preparations after trypsin activation had similar peptide maps. These results indicate that the toxin obtained from culture fluid was a partially activated form, and that its molecular conformation was different from that of the toxin from cell extract. Differences in specific activity and activation ratio by trypsin treatment may be due to differences in the conformation of the toxin molecules.

Binding of Clostridium botulinum neurotoxin to gangliosides

The binding characteristics of Clostridium botulinum neurotoxins of types B, C1, and F to gangliosides was studied by thin layer chromatography plate and microtiter plate methods at low (10 mM NaCl in 10 mM Tris-HCl buffer, pH 7.2) or high (150 mM NaCl in 10 mM Tris-HCl buffer, pH 7.2) ionic strengths and at 0 or 37 degrees C. The three types of toxins bound exclusively to three kinds of gangliosides, GD1a, GD1b, and GT1b, in both the thin layer chromatography plate and the microtiter plate methods. Type C1 toxin bound to the three gangliosides under all the conditions, while type B and F toxins bound only at low ionic strength and 37 degrees C. At low ionic strength, the binding kinetics for the three toxins was monophasic in Scatchard plots, and the association constants obtained in the microtiter plate system were 2-4 X 10(8) M-1. In contrast, the binding kinetics of type C1 toxin in high ionic strength was biphasic in the Scatchard plot, and two association constants were obtained in the microtiter plate system. The heavy chain facilitated the binding of the toxin to the gangliosides. These results indicate that different types of botulinum toxins bind to the gangliosides under different optimal conditions and that gangliosides may not be the common receptor for all types of botulinum toxins. The gangliosides may bind to type C1 toxin together with other potential receptor(s) on synaptosomal membranes.

Reaction of the hydrated electron with histone H1 and related compounds studied by e.s.r. and spin-trapping

The reactions of the hydrated electron with histone H1, protamine and related compounds (poly-L-lysine, poly-L-arginine and poly-D,L-alanine) were investigated by the spin-trapping technique. In order to identify the radical structure of the spin-adducts originating from macromolecules, the usual spin-trapping technique was developed as follows: N2-saturated aqueous solutions of proteins containing sodium formate were X-irradiated (4.5 kGy) in the presence of 2-methyl-2-nitrosopropane (MNP) as a spin-trap. The side-products due to the self trapping of MNP radicals were then removed from the spin-adducts of the proteins by a Sephadex G-25 column. Finally the spin-adducts were enzymatically digested to transform the broad e.s.r. signals due to slow tumbling of nitroxyl radicals to identifiable ones. The e.s.r. spectra obtained for all samples showed that the deaminated radical, R--CH--CO--NH--(R:amino acid side chain), was produced. Furthermore, polyacrylamide gel electrophoresis of the irradiated protamine and histone H1 indicated reduction of molecular size. These results confirm that hydrated electrons react with proteins and induce the deamination reaction which leads to main-chain scission.