Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adherence of Plasmodium falciparum-infected erythrocytes (IE) to the venular endothelium in brain and other organs is characteristic of cerebral malaria, an often fatal complication in infected individuals. It has been shown that cytoadherence may be mediated through interaction of IE with glycoproteins on host target cell surfaces, including CD36 (GPIV), intercellular adhesion molecule-1 (ICAM-1), and thrombospondin. Inhibitors of glycoprotein synthesis and processing were tested for their abilities to decrease IE adherence to C32 human melanoma cells. The alpha-glucosidase inhibitor, castanospermine, was effective in disrupting cytoadherence in vitro when incubated with C32 cells (IC50 = 600-700 microM). Castanospermine-6-butyrate was even more effective than the parent compound (IC50 = 9 microM) in disrupting cytoadherence. The mannosidase inhibitors, swainsonine and deoxymannojirimycin, had no effect on cytoadherence at concentrations up to 2 mM. No effect on cytoadherence was observed when the glucosidase and mannosidase inhibitors were incubated with IE rather than the C32 cell cultures. The level of CD36 on the C32 cell surface was decreased as measured by fluorescence-activated cell sorting (FACS) analysis with the same inhibitors which inhibited cytoadherence. Cells labeled with fluorescein isothiocyanate (FITC) OKM5 monoclonal antibody, which recognizes CD36 and disrupts cytoadherence, showed decreased fluorescence when treated with tunicamycin and castanospermine-6-butyrate but not when treated with swainsonine or deoxymannojirimycin. ICAM-1 levels, as measured by surface labeling of C32 cells with FITC CD54 monoclonal antibody, were decreased in cells treated with tunicamycin. However, incubation of cells with castanospermine-6-butyrate or deoxymannojirimycin decreased cell surface ICAM-1 levels only slightly. These findings suggest that (1) in C32 cells, levels of cell surface CD36, and not ICAM-1, change proportionally to the level of cytoadherence; (2) drugs which can affect the carbohydrate moiety of cellular glycoproteins decrease cytoadherence of IE to C32 cells; and (3) protection against the development of cerebral malaria may be possible with inhibitors of glycoprotein biosynthesis.
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PMID:Disruption of Plasmodium falciparum-infected erythrocyte cytoadherence to human melanoma cells with inhibitors of glycoprotein processing. 171 Jan 20

The antimetastatic activity of ten compounds structurally related to nojirimycin A was examined using a pulmonary metastatic model of mouse B16 melanoma. Nojirimycin B, deoxynojirimycin, D-gluco-delta-lactam, CP3068 and CP3069 are structural analogues of nojirimycin A, and showed potent or moderate antimetastatic activities. Nojirimycin A, nojirimycin B, deoxynojirimycin and D-gluco-delta-lactam showed potent or moderate inhibitory activities against alpha-glucosidase, beta-glucosidase and beta-mannosidase, but CP3068 and CP3069 in which the structures were related to D-gluco-delta-lactam showed no inhibitory activities. CP3041, CP3042, CP3043, CP3045 and CP3048 are analogues of sodium D-glucaro-delta-lactam (ND2001), a carboxy derivative of nojirimycin A, and showed potent or moderate antimetastatic activities. But no analogue was superior to ND2001 concerning with antimetastatic and anti-beta-glucuronidase activities. CP3041 and CP3042 showed potent and moderate inhibitory activities against beta-glucuronidase, respectively, but CP3043, CP3045 and CP3048 showed little or no activities.
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PMID:Inhibition of mouse tumor metastasis with nojirimycin-related compounds. 862 56

In this study we have explored the endoplasmic reticulum associated events accompanying the maturation of the tyrosinase-related protein-1 (TRP-1) nascent chain synthesized in mouse melanoma cells. We show that TRP-1 folding process occurs much more rapidly than for tyrosinase, a highly homologous protein, being completed post-translationally by the formation of critical disulfide bonds. In cells pretreated with dithiothreitol (DTT), unfolded TRP-1 is retained in the endoplasmic reticulum by a prolonged interaction with calnexin and BiP before being targeted for degradation. The TRP-1 chain was able to fold into DTT-resistant conformations both in the presence or absence of alpha-glucosidase inhibitors, but folding occurred through different pathways. During the normal folding pathway, TRP-1 interacts with calnexin. In the presence of alpha-glucosidase inhibitors, the interaction with calnexin is prevented, with TRP-1 folding being assisted by BiP. In this case, the process has similar kinetics to that of untreated TRP-1 and yields a compact form insensitive to DTT as well. However, this form has different thermal denaturation properties than the native conformation. We conclude that disulfide bridge burring is crucial for the TRP-1 export. This suggests that although various folding pathways may complete this process, the native form may be acquired only through the normal unperturbed pathway.
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PMID:Folding and maturation of tyrosinase-related protein-1 are regulated by the post-translational formation of disulfide bonds and by N-glycan processing. 1091 99

Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the Clinical Studies knowledge area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: 81C6; Adefovir dipivoxil, Agalsidase alfa, AGM-1470, albumin interferon alfa, alefacept, alosetron hydrochloride, anakinra, anti-CTLA-4 Mab, aprepitant, aripiprazole, atazanavir; BAY-43-9006, BBR-3438, beta-L-Fd4C, bimatoprost, bortezomib, bosentanBR96-doxorubicin; Caspofungin acetate, ciclesonide, cilengitide, cilomilast, COL-1621, COL-3, CpG-7909, cyclosporine; DCVax-Brain, dexmethylphenidate hydrochloride, dexosome vaccine (melanoma), donepezil hydrochloride, drotrecogin alfa (activated), DTI-015, [99Tc]-DTPA-mannosyldextran, duloxetine hydrochloride; Emivirine, emtricitabine, entecavir, epothilone B, estradiol-MNP, etonogestrel/etonogestrel/ethinylestradiol, etoricoxib; Febuxostat, fondaparinux sodium, fosamprenavir calcium; Gefitinib, GVS-111; Heparinase I, HspE7, human alpha-glucosidase, human insulin; Imatinib mesylate, INGN-241, interferon alfa B/D hybrid, interferon alfa Biphasix, ISIS-14803; Lanicemine hydrochloride, 1311-lipiodol, liposome-encapsulated mitoxantrone, lixivaptan, lumiracoxib, lupus-AHP, LY-466700; Marimastat, MEN-10755, micafungin sodium; Nitronaproxen, NSC-683864 Omalizumab, oral insulin; Palonosetron hydrochloride, peginterferon alfa-2a, pimecrolimus, pralnacasan, pramlintide acetate, pregabalin, pyrazoloacridine; R-165335, ranolazine, risperidone, RPR-109881;, RSD-1235, Satraplatin, seocalcitol, sertindole, SMART anti-interferon gamma antibody, sulfasalazine; T-138067, TAK-013, tegaserod maleate, telithromycin, tenofovir disoproxil fumarate, teriparatide, tiotropium bromide, tipifarnib, TP-38; Valdecoxib, vatalanib succinate, voriconazole; ZD-9331.
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PMID:Gateways to clinical trials. 1269 Jul 8

The 40% ethanol eluent of the fraction of hot-water extract from adzuki beans (EtEx.40) adsorbed onto DIAION HP-20 resin has many biological activities, for example, antioxidant, antitumorigenesis, and intestinal alpha-glucosidase suppressing activities. This study examined the inhibitory effect of EtEx.40 on experimental lung metastasis and the invasion of B16-BL6 melanoma cells. EtEx.40 was found significantly to reduce the number of tumor colonies. It also inhibited the adhesion and migration of B16-BL6 melanoma cells into extracellular matrix components and their invasion into reconstituted basement membrane (matrigel) without affecting cell proliferation in vitro. These in vivo data suggest that EtEx.40 possesses a strong antimetastatic ability, which might be a lead compound in functional food development.
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PMID:Potential ability of hot water adzuki (Vigna angularis) extracts to inhibit the adhesion, invasion, and metastasis of murine B16 melanoma cells. 1578 70

Tyrosinase, a type I membrane glycoprotein, is synthesized and glycosylated in the endoplasmic reticulum (ER) and Golgi. The enzyme is subsequently transported to melanosomes where it participates in melanogenesis. Previous studies showed that the disruption of early ER N-glycan processing by deoxynojirimycin (DNJ), an inhibitor of alpha-glucosidase, suppresses tyrosinase enzymatic activity and melanogenesis. However, the disruption of late glycan processing, mainly performed by ER and Golgi alpha-1,2-mannosidases, on tyrosinase enzymatic activity and melanogenesis remains to be investigated. Following treatment of HM3KO human melanoma cells with deoxymannojirimycin (DMJ), an inhibitor of alpha-1,2-mannosidase, transport of tyrosinase to the melanosome, enzymatic activity, and melanogenesis were reduced in a dose-dependent manner. However, DMJ did not directly inhibit tyrosinase enzymatic activity and expression. Interestingly, an extract of Streptomyces subrutilus culture medium (ESSCM) containing DMJ and DNJ as the main components inhibited glycosylation and transport of tyrosinase to the melanosome as well as melanin synthesis, but with no negative effects on cell viability. These inhibitory effects of ESSCM were stronger than those of DMJ or DNJ alone. Tyrosinase glycosylation and melanogenesis in HM3KO melanoma cells were more effectively inhibited by DMJ and DNJ combined than DMJ or DNJ alone. Accordingly, we propose that ESSCM is a potential candidate for treating undesirable hyperpigmentation conditions, such as melasma, postinflammatory melanoderma, and solar lentigo.
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PMID:Influence of N-glycan processing disruption on tyrosinase and melanin synthesis in HM3KO melanoma cells. 1722 24