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Antibacterial activity of Aframomum melegueta was tested on salmonella spp, Escherichia coli, Shigella spp and klebsiella spp. Ethanol and distilled water were used as solvents for the extraction of the plant. The ethanolic extract was found to be most effective at high concentration of 50mg/ml on all the isolates. The zones of inhibition of klebsiella spp, salmonella spp, E. coli and Shigella spp are 30mm,15mm,20mm,and 15mm respectively with ethanolic extract. The aqueous extract was found to be less effective when compared with ethanolic extract.The phytochemcial analysis carried out on Aframomum melegueta revealed the presence of alkaloids, tannins, saponin, steroids, cardiacglycoside, flavonoid, terpenoids and phenol. The presence of these phytochemcials support the use of this plant as antimicrobial agent. Aframomum melegueta can therefore be used as antimicrobial agent against the groups of Enterobacteriaceae tested.

Intracellular proteins are targeted for degradation by the covalent attachment of chains of the small protein ubiquitin; a process known as ubiquitylation. Many proteins are phosphorylated prior to ubiquitylation, and therefore ubiquitylation and degradation of these proteins is regulated by kinase activity and signalling cascades. Many ubiquitylated proteins are degraded by the 26 S proteasome complex, which is found in the cytosol and nucleus. The 26 S proteasome consists of a 20 S core with proteolytic activity and 18 S regulatory complexes containing ATPases and ubiquitin-chain-binding proteins. Proteins degraded by the ubiquitin-proteasome pathway include cyclins and other regulators of the cell cycle, and transcription factors. Abnormal polypeptides are also degraded by the ubiquitin pathway, including abnormal polypeptides in the endoplasmic reticulum, which are translocated back out of the endoplasmic reticulum prior to ubiquitylation and degradation by the proteasome. The ubiquitin-proteasome pathway is implicated in numerous diseases including cancer and neurodegenerative diseases.

We have examined the distribution of ubiquitin and the related ubiquitin cross-reactive protein (UCRP) in paraffin-embedded sections of human and baboon endometrium and decidua by immunoperoxidase or immunofluorescence cytochemistry with antibodies raised against ubiquitin, UCRP, CD45, and insulin-like growth factor-binding protein-1. Anti-ubiquitin immunoreactivity was present in the nonpregnant endometrium, particularly in the glandular epithelial cells, and up-regulated in endometrial stromal cells as they decidualized at the beginning of pregnancy. Anti-UCRP immunoreactivity was absent from nonpregnant tissue but accumulated to high levels in decidual cells during pregnancy. Western blotting indicated that immunoreactivity was primarily due to the presence of ubiquitin and UCRP conjugated to other proteins, and that although levels of ubiquitin-protein conjugates do not change substantially during pregnancy, decidualization is accompanied by the appearance of conjugates of UCRP. Baboon uterine tissues demonstrated a similar distribution of the two proteins, which indicates that the baboon may be a useful model for study of the role of the ubiquitin system and UCRP in the establishment of pregnancy in humans.

Ubiquitin-protein conjugates are found by immunogold electron microscopy to be enriched (12-fold) in the lysosomal compartment of 3T3-Ll fibroblasts. Treatment of fibroblasts with the cysteine protease inhibitor E-64 leads to an expansion of the lysosomal compartment and as a result an increase in the cellular content of ubiquitin-protein conjugates. There is no change in the specific enrichment of ubiquitin-protein conjugates in the lysosomal compartment following E-64 treatment. The results suggest that some ubiquitin-protein conjugates may normally be degraded lysosomally following sequestration by microautophagy and imply that protein ubiquitination may be one of the signals for protein uptake into lysosomes.

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Several glycolytic enzymes (lactate dehydrogenase, pyruvate kinase, glyceraldehyde-3-phosphate dehydrogenase) were radiolabelled by [125I]iodination, conjugation with 125I-labelled Bolton & Hunter reagent and reductive [3H]methylation, and their degradative rates after microinjection into 3T3-L1 cells compared with that of the extracellular protein bovine serum albumin. Although the albumin remains largely cytosolic in recipient cells, the glycolytic enzymes rapidly (less than 30 min) become insoluble, as measured by detergent and salt extractions. The microinjected glycolytic enzymes appear to form disulphide-linked aggregates, are found in a cell fraction rich in vimentin-containing intermediate filaments and histones (nuclear-intermediate-filament fraction), and are degraded slowly by a lysosomal mechanism, as judged by the effects of inhibitors (NH4Cl, leupeptin, 3-methyladenine). 125I-labelled bovine serum albumin appears to be degraded rapidly and non-lysosomally. Prolonged treatment (96 h) of cultured cells with leupeptin results in the accumulation of pulse-labelled ([35S]methionine for 24 h) endogenous cell proteins in the detergent-and salt-non-extractable residue, but NH4Cl and 3-methyladenine do not have this effect. The findings are in terms of the interpretation of experiments involving microinjection of proteins to study intracellular protein protein degradation by autophagy.