The sugar-binding specificity of the toxic lectins from Abrus pulchellus seeds was investigated by combination of affinity chromatography of glycopeptides and oligosaccharides of well-defined structures on a lectin-Sepharose column and measurement of the kinetic interactions in real time towards immobilized glycoproteins. The lectins showed strong affinity for a series of bi- and triantennary N-acetyllactosamine type glycans. The related asialo-oligosaccharides interact more strongly with the lectins. The best recognized structures were asialo-glycopeptides from fetuin. Accordingly, the kinetic interaction with immobilized asialofetuin was by far the most pronounced. Human and bovine lactotransferrins and human serotransferrin interacted to a lesser extent. The interaction with asialofetuin was inhibited by galactose in a dose dependent manner. Lactose, N-acetyllactosamine and lacto-N-biose exhibited similar degree of inhibition while N-acetylgalactosamine was a poor inhibitor. These results suggested that the carbohydrate-binding site of the Abrus pulchellus lectins was specific for galactose and possess a remarkable affinity for the sequences lactose [-D-Gal-(14)-D-Glc], N-acetyllactosamine [-D-Gal-(14)-D-GlcNAc] and lacto-N-biose [-D-Gal-(13)-D-GlcNAc]. 相似文献
Vaccine adjuvants are substances associated with antigens that are fundamental to the formation of an intense, durable, and fast immune response. In this context, the use of vaccine adjuvants to generate an effective cellular immune response is crucial for the design and development of vaccines against visceral leishmaniasis. The objective of this study was to evaluate innate inflammatory response induced by the vaccine adjuvants saponin (SAP), incomplete Freund's adjuvant (IFA), and monophosphoryl lipid A (MPL). After a single dose of adjuvant was injected into the skin of mice, we analyzed inflammatory reaction, selective cell migration, and cytokine production at the injection site, and inflammatory cell influx in the peripheral blood. We found that all vaccine adjuvants were able to promote cell recruitment to the site without tissue damage. In addition, they induced selective migration of neutrophils, macrophages, and lymphocytes. The influx of neutrophils was notable at 12 h in all groups, but at other time points it was most evident after inoculation with SAP. With regard to cytokines, the SAP led to production of interleukin (IL)-2, IL-6, and IL-4. IFA promoted production of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-6, IL-17, IL-4, and IL-10. We also observed that MPL induced high production of IL-2, TNF-α, and IFN-γ, in addition to IL-6, IL-17, and IL-10. In peripheral blood, values of certain cell populations in the local response changed after stimulation. Our data demonstrate that the three vaccine adjuvants stimulate the early events of innate immune response at the injection site, suggesting their ability to increase the immunogenicity of co-administered antigens. Moreover, this work provides relevant information about elements of innate and acquired immune response induced by vaccine adjuvants administered alone. 相似文献
The effect of viruses on the microbial loop, with particular emphasis on bacteria, was investigated over an annual cycle in
2003–2004 in Lake Druzhby and Crooked Lake, two large ultraoligotrophic freshwater lakes in the Vestfold Hills, Eastern Antarctica.
Viral abundance ranged from 0.16 to 1.56 × 109 particles L-1;1 and bacterial abundances ranged from 0.10 to 0.24 × 109 cells L-1;1, with the lowest bacterial abundances noted in the winter months. Virus-to-bacteria ratios (VBR) were consistently low in
both lakes throughout the season, ranging from 1.2 to 8.4. lysogenic bacteria, determined by induction with mitomycin C, were
detected on three sampling occasions out of 10 in both lakes. In Lake Druzhby and Crooked Lake, lysogenic bacteria made up
between 18% and 73% of the total bacteria population during the lysogenic events. Bacterial production ranged from 8.2 to
304.9 × 106 cells L-1;1 day-1;1 and lytic viral production ranged from 47.5 to 718.4 × 106 viruslike particles L-1;1 day-1;1. When only considering primary production, heterotrophic nanoflagellate (HNF) grazing and viral lysis as the major contributors
to the DOC pool (i.e., autochthonous sources), we estimated a high contribution from viruses during the winter months when
>60% of the carbon supplied to the DOC pool originated from viral lysis. In contrast, during the summer <20% originated from
viral lysis. Our study shows that viral process in ultraoligotrophic Antarctic lakes may be of quantitative significance with
respect to carbon flow especially during the dark winter period. 相似文献
Structural genomics efforts have produced structural information, either directly or by modeling, for thousands of proteins
over the past few years. While many of these proteins have known functions, a large percentage of them have not been characterized
at the functional level. The structural information has provided valuable functional insights on some of these proteins, through
careful structural analyses, serendipity, and structure-guided functional screening. Some of the success stories based on
structures solved at the Northeast Structural Genomics Consortium (NESG) are reported here. These include a novel methyl salicylate
esterase with important role in plant innate immunity, a novel RNA methyltransferase (H. influenzae yggJ (HI0303)), a novel spermidine/spermine N-acetyltransferase (B. subtilis PaiA), a novel methyltransferase or AdoMet binding protein (A. fulgidus AF_0241), an ATP:cob(I)alamin adenosyltransferase (B. subtilis YvqK), a novel carboxysome pore (E. coli EutN), a proline racemase homolog with a disrupted active site (B. melitensis BME11586), an FMN-dependent enzyme (S. pneumoniae SP_1951), and a 12-stranded β-barrel with a novel fold (V. parahaemolyticus VPA1032). 相似文献
Seeking insight into the possible role of estrogens in prostate cancer (PCa) evolution, we assayed serum E2, estrone (E1), and estrone sulfate (E1S) in 349 PCa and 100 benign prostatic hyperplasia (BPH) patients, and in 208 control subjects in the same age range (50–74 years).
E1 (pmol/L ± S.D.) and E1S (nmol/L ± S.D.) in the PCa and BPH patients (respectively 126.1 ± 66.1 and 2.82 ± 1.78, and 127.8 ± 56.4 and 2.78 ± 2.12) were significantly higher than in the controls (113.8 ± 47.6 and 2.11 ± 0.96). E2 was not significantly different among the PCa, BPH, and control groups. These assays were also carried out in PCa patients after partition by prognosis (PSA, Gleason score (GS), histological stage, and surgical margins (SM)). Significantly higher E1S levels were found in PCa with: PSA > 10 ng/L (3.05 ± 1.92) versus PSA ≤ 10 ng/mL (2.60 ± 1.55), stage pT3-T4 (2.99 ± 1.80) versus pT2 (2.58 ± 1.58), and positive (3.26 ± 1.95) versus negative margins (2.52 ± 1.48). E1 was higher in poor- than in better-prognosis PCa. E2 was significantly higher in PCa with GS ≥ 4 + 3 (109.5 ± 43.8) versus GS ≤ 3 + 4 (100.6 ± 36.5) and increased significantly when GS increased from 3 + 3 to 4 + 4. Estrogens, especially E1S appeared to be possible markers of PCa progression.
Attempting to identify potential sources of E2 in PCa according to prognosis, as well as in BPH, we found a significant correlation coefficient between E1S and E2 (0.266–0.347) in poor-prognosis PCa and no correlation in BPH (0.026) and better-prognosis PCa (0.013–0.104).
It is as though during progression of PCa from good to poor prognosis there were a shift in the E1 to E2 metabolic pathway from predominantly oxidative to predominantly reductive. 相似文献
Length–weight relationships (LWRs) were determined for four fish species from two drainage areas, those of the Itapemirim and Jucu River, in the state of Espírito Santo, southeastern Brazil. Fishes were collected between May 2015 and November 2016, with gill nets, casting net, dip net, and sieve. Herein are presented LWRs for Astyanax lacustris, Astyanax taeniatus, Hyphessobrycon bifasciatus and Oligosarcus acutirostris. 相似文献
(?)-Cubebin (CUB), isolated from seeds of Piper cubeba, was used as starting material to obtain the derivatives (?)-hinokinin (HK) and (?)-O-benzyl cubebin (OBZ). Using paw edema as the experimental model and different chemical mediators (prostaglandin and dextran), it was observed that both derivatives were active in comparison with both negative (5% Tween® 80 in saline) and positive (indomethacin) controls. The highest reduction in the prostaglandin-induced edema was achieved by OBZ (66.0%), while HK caused a 59.2% reduction. Nonetheless, the dextran-induced paw edema was not significantly reduced by either of the derivatives (HK or OBZ), which inhibited edema formation by 18.3% and 3.5%, respectively, in contrast with the positive control, cyproheptadine, which reduced the edema by 56.0%. The docking analysis showed that OBZ presented the most stable ligand-receptor (COX-2 – cyclooxygenase-2) interaction in comparison with CUB and HK. 相似文献