Purification and biochemical characterization of a D-galactose binding lectin from Japanese sea hare (Aplysia kurodai) eggs.

A lectin was purified from Japanese sea hare Aplysia kurodai by lactosyl-agarose affinity chromatography. The molecular mass of the lectin was determined to be 56 and 32 kDa by SDS-PAGE under non-reducing and reducing conditions, respectively. It was found to agglutinate trypsinized and glutaraldehyde-fixed rabbit and human erythrocytes in the absence of divalent cations. The lectin exhibited stable thermo-tolerance as it retained hemagglutinating activity for 1 h even at 80 degrees C and showed stability at pH 10. By contrast, it was very sensitive at pH less than 5 and in the presence of the sulfhydryl-group preserving reagent, beta-mercaptoethanol. The hemagglutinating activity by the lectin was specifically inhibited by D-galactose, galacturonic acid, methyl-alpha- and methyl-beta-D-galactopyranoside, lactose, melibiose, and asialofetuin. The association rate constant (k(ass)) and dissociation rate constant (k(diss)) were determined for the lectin to be 4.3 x 10(5) M(-1) x sec(-1) and 2.2 x 10(-3) sec(-1), respectively, using a surface plasmon resonance biosensor. The lectin moderately inhibited cell proliferation in the P388 cell line dose dependently. Interestingly, lectin-treated cells did not show a fragmented DNA ladder as is caused by apoptosis, suggesting that the cell proliferation inhibition was caused by another unknown mechanism.

[Drug sensitivity, conjugative R plasmids and plasmid profiles of Salmonella isolated from humans with infectious enteritis].

Using 92 Salmonella strains isolated from patients suspected of having infectious diseases of the intestinal tract who visited 13 hospitals in Japan during the six years between 1991 and 1996, we investigated the drug susceptibility, prevalence of conjugative R plasmid, and the plasmid profiles. 1) Of the bacterial isolates tested, 52.2% showed drug-resistance. Regarding the drug-resistance patterns, 70.8% of the isolates were resistant to a single drug, while 29.2% were multi drug-resistant. 2) Dividing the resistance patterns by the serotypes, among Salmonella Enteritidis isolates, single-drug resistance to SM was the most frequent, being detected in 27 isolates. Single-drug resistance to NA and two-drug resistance to SM/TC were the second-most frequent, each being detected in isolates. Among Salmonella Hadar isolates, four isolates showed two-drug resistance to SM/TC, and one isolate showed single-drug resistance to TC. Among Salmonella Typhimurium isolates, one isolate each showed three-drug resistance to ABPC/CER/KM and KM/TC/CP. Among Salmonella Agona isolates, one isolate each showed two-drug resistance to SM/TC and single-drug resistance to SM. Among Salmonella Derby isolates, two isolates showed single-drug resistance to SM. 3) The prevalence of conjugative R plasmid was investigated in 48 drug-resistant isolates, and six isolates (12.5%) contained the plasmid. 4) The prevalence of the plasmid was investigated in 29 drug-resistant S. Enteritidis isolates, and 22 isolates (75.9%) contained the plasmid. These isolated were classified by the plasmid profiles into types H1 to H7. 5) Regarding the plasmid profiles of the S. Enteritidis isolates, a position corresponding to 60 Kbp was the most frequently detected in 90.5%.

[Substance isolated from the kelp rhizoid identified as L-tryptophan shows high inhibition of breast cancer].

In general, the root of a seaweed is poorly developed as compared with its thallus and is called the rhizoid or holdfast. In Laminaria, belonging to Phaeophyceae, although the thallus is used for food, the rhizoid is considered an unuseful natural resource. We attempted to detect anti-breast cancer substances from that resource. As a result, a substance having a weak absorptivity to aluminium oxide and Sephadex G-25 was found. According to analysis of the FAB-MS spectra and 1H NMR spectra, the substance was identified as tryptophan, an amino acid. Finally, it was concluded by a chiral column-HPLC method that the tryptophan was the L-form.

Architecture of alkaline-soluble and bioactive polysaccharide from the kernels of Prunus mume Sieb. et Zucc. assessed by anti P-1 antibody.

P-1 was partially hydrolyzed with 0.01, 0.05, and 0.1 M trifluoroacetic acid (TFA), successively, and the dialyzable (E-1, E-2, and E-3) and non-dialyzable (I-1, I-2, and I-3) fractions were prepared and analyzed chemically and immunochemically. Either I-1 or E-1 reacted with anti P-1 serum as strongly as P-1 and were mitogenic. The cross-reactivity of I-2 and I-3 was less than I-1 with anti P-1 serum. However, they were as mitogenic as I-1. The cross-reactivity of E-2 and E-3 to anti P-1 serum was also very weak, and they were not mitogenic. The E-1 fraction had a similar sugar composition to I-1 and P-1. E-2 was a monosaccharide, all of Ara, and would be from the linkage of furanosyl residues in P-1. The composition of E-3 was free from Ara and the structure of E-3 was similar to that of I-3. E-3 would be considered to be deleted arabinofuranose from E-1. These results suggest that the mitogenic activity measured by the alkaline phosphatase assay is a property of the core part, I-3, but that P-1 contains several epitopes other than the core part by the immunochemical analysis.

Immunochemical characterization of alkaline-soluble polysaccharide, P-1, from the kernels of Prunus mume Sieb. et Zucc.

Polyclonal antibodies against P-1, a pectic polysaccharide fraction extracted with 0.5 M NaOH from the kernels of Prunus mume and consisted of arabino-galacturonan, and I-3, the partial acid (0.1 M trifluoroacetic acid) hydrolysate of P-1, were prepared in Japanese white rabbits. Competitive ELISA experiments strongly suggested that anti P-1 and anti I-3 antibodies were different but P-1 and I-3 cross-reacted with each other to recognize a partly similar epitope structure. The reactivities of polysaccharide fractions from the raw flesh of P. mume, and the kernels of apricot and peach extracted with either water or sodium hydroxide were examined using both antisera by the indirect competitive ELISA method. The polysaccharide fractions extracted with sodium hydroxide solutions had the reactivities but not those extracted with cold and hot water. These facts suggested that the similar structure of polysaccharides to P-1 was present in the flesh of P. mume and the kernels of apricot and peach. However, neither pectin of apple nor citrus had reactivity with each antiserum. P-1 would be different in chemical structure from a commercially available pectin, a water-soluble polysaccharide from apple and citrus.

Structural analysis of alkaline-soluble polysaccharide, P-1, from the kernels of Prunus mume Sieb. et Zucc.

A polysaccharide fraction extracted with cold 0.5 M NaOH from the kernels of Prunus mume exhibited some biological activities. A polysaccharide, P-1, was purified from the 0.5M NaOH extract by ion-exchange chromatography and gel-filtration. The results of the structural analysis of P-1 to determine the relationship between the activities and the structure are described in this paper. In the mild acid hydrolysis of P-1, the nondialyzable hydrolysate (I-3) believed to be its core portion was obtained. The yield of I-3 was 26.0% and contained 59.8% uronic acid as galacturonic acid (GalA). The neutral sugars of I-3 were composed of rhamnose, xylose and galactose in a molar ratio of 1.0:3.4:0.3 following analysis by gas-liquid chromatography. The molecular weight of I-3 was estimated to be ca. 14000 by gel-filtration on Toyopearl HW55F. I-3 exhibited the mitogenic activity toward spleen cells as well as P-1. These facts appeared to confirm that I-3 was the core part of P-1 and important for its biological activity. I-3 was successfully reduced by the Taylor and Conrad method to avoid so much repetition. Methylation analysis of the reduced hydrolysate by gas-liquid chromatography and gas chromatography-mass spectroscopy showed that the ratio of 1,4-linked galactopyranosyl and 1,3,4-linked galactopyranosyl residues were significantly increased in comparison with native I-3. These results suggested that I-3 was composed of 1,4- and 1,3,4-linked galacturonic acid residues in the main chain.

Biological activity and structural characterization of alkaline-soluble polysaccharides from the kernels of Prunus mume Sieb. et Zacc.

The fruits of Prunus mume Sieb. et Zacc. (Japanese name, ume) have been used as a traditional drug and health food. In order to study the active components of P. mume, the polysaccharide fractions were extracted with cold water, hot water and aqueous sodium hydroxide from the kernels of P. mume. We found that some of the polysaccharide fractions exhibited various types of biological activities such as mitogenesis, activation of the alternative pathway of complement and activation of clot formation in human plasma. A polysaccharide, P-1, obtained from the cold 0.5 M NaOH extract was purified by ion-exchange chromatography and gel-filtration, P-1 contained 62.0% neutral sugar as glucose and 38.4% uronic acid (as galacturonic acid), and was free from protein. The neutral sugars of P-1 were arabinose, xylose, rhamnose and galactose in a molar ratio of 9.4:3.4:1.1:1.0, following analysis by gas-liquid chromatography. In addition, galacturonic acid was identified by thin-layer chromatography. The molecular weight of P-1 was found to be more than 2,000,000 by gel-filtration on Toyopearl HW 65F. P-1 showed mitogenic activity towards spleen cells of both C3H/HeN and C3H/HeJ, suggesting that it was free from bacterial endotoxic lipopolysaccharides.

[Antimutagenic activities of hexane extracts of the fruit extract and the kernels of Prunus mume Sieb. et Zucc].

Antimutagenic activities of hexane extracts obtained from the fruit extract (UE) and the Kernels (KE) of P. mume were examined. These extracts showed inhibitory activities to known mutagens, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide, benzo[alpha]pyrene and aflatoxin B1 in the Ames assay using Salmonella typhimurium TA100 and TA98 strains. The UE and KE fractions were then separated by silicic acid column chromatography with a stepwise elution method using ether-hexane. The location of the active substances in the fractions was also determined by thin-layer chromatography. Consequently, it was found that the effective substances for the desmutagenicity were fatty acids, and identified by gas liquid chromatography, mainly as oleic acid, linoleic acid and linolenic acid in UE, and mainly as oleic acid and linoleic acid in KE, respectively.