Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1519176 (PSA)
 5,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Homopolymeric alpha-2,8-linked sialic acid (PSA) has been found as a capsular component of sepsis- and meningitis-causing bacterial pathogens, and on eukaryotic cells as a post-translational modification of the neural cell adhesion molecule (NCAM). The polysaccharide is specifically recognized and degraded by a phage-encoded enzyme, the endo-N-acetylneuraminidase E (Endo NE). Endo NE therefore has become a valuable tool in the study of bacterial pathogenesis and eukaryotic morphogenesis. In this report we describe the molecular cloning of Endo NE and the expression of a functionally active recombinant enzyme. The cloned DNA sequence (2436 bp) encodes a polypeptide of 811 amino acids, which at the 5' end contains a totally conserved neuraminidase motif. Expressed in Escherichia coli, the enzyme migrates as a single band of approximately 74 kDa in SDS-PAGE. A central domain of 669 amino acid residues is about 90% homologous to the recently cloned Endo NF. Both phage-induced lysis of bacteria and the catalysis of PSA degradation by the recombinant enzyme are efficiently inhibited by a polyclonal antiserum raised against the intact phage particle. The C-terminal region seems to be essential to enzymatic functions, as truncation of 32 amino acids outside the homology domain completely abolishes Endo NE activity. Our data also indicate that the 38 kDa protein, previously assumed to be a subunit of the Endo NE holoenzyme, is the product of a separate gene locus and is not necessary for in vitro depolymerase activity.
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PMID:Molecular cloning and functional expression of bacteriophage PK1E-encoded endoneuraminidase Endo NE. 756 5

We have examined 82 patients with hormonoresistant prostate cancer in a retrospective study. Bone and lymph node metastases were observed in 94% and 30% of patients respectively. However, the visceral metastases were frequent: liver (17%), lung (7%), bone marrow (4%), meningitis (4%). PSA is constantly high but 28% of the patients have elevated NSE, which is correlated with lymph node or visceral metastases. ACE is elevated in 27% of cases. Objective and palliative effect of chemotherapy is marked for weekly doxorubicin, prednisone with mitoxantrone and etoposide associated with platin-salts for prostatic carcinoma with neuroendocrine differentiation. This study suggests the presence of different subpopulations of patients with specific evolutive patterns, thus further specific therapy should be evaluated.
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PMID:[Study of the hormone-refractory prostate cancer clinical practice in an anti-cancer center]. 1179 13