Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To define the histogenesis of the Paget cell and possibly identify differences in cells from the two sites, six vulvar and 23 mammary specimens from Paget's disease lesions were studied for immunocytochemical antigens. All vulvar and 21 (91%) mammary lesions were strongly reactive for glandular cytokeratin. All lesions showed immunopositive Paget cells with epithelial membrane antigen (EMA). An apocrine antigen, gross cystic disease fluid protein (GCDFP-15), decorated 66.5% and 56.5% of extramammary and mammary lesions, respectively. All vulvar Paget cells stained for carcinoembryonic antigen (CEA), a frequency significantly greater than the 35% in mammary lesions (p = 0.02). However, CEA is expressed by both eccrine and apocrine sweat glands and their tumors. Vulvar Paget cells were negative for lysozyme, casein, lactalbumin, and S100 protein, compared with 9%, 4%, 4%, and 26% in nipple lesions. S100 protein expression is similar to that in mammary ductal carcinoma (32%). The glandular origin of both extramammary and mammary Paget cells is indicated by the presence of glandular cytokeratin, EMA, and CEA. Approximately 60% of all cases in both sites showed evidence of apocrine derivation (GCDFP-15 positivity). Variable antigen expression suggests possible malignant transformation of pluripotent germinative cells able to differentiate in an apocrine or an eccrine direction, or in both.
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PMID:Histogenesis of extramammary and mammary Paget cells. An immunohistochemical study. 254 98

Although the primary cell type in human osteosarcoma is usually a neoplastic osteoblast, numerous other mesenchymal cell types may coexist in the same tumor. Previously described cloned, long-term osteosarcoma cell lines have had an osteoblastic phenotype. In this report, we describe a nonosteoblastic, long-term cell line derived from an osteosarcoma in a patient with Paget's disease. The cell line (FM-2) is nontransformed in having a low saturation density and anchorage-dependent growth, and it is nontumorigenic in nude mice. Important features of its fine structure include numerous elongated mitochondria, abundant Golgi and lysosomes, and a poorly developed rough endoplasmic reticulum. The line has high levels of lysosomal enzymes (acid phosphatase and N-acetylglucosaminidase) and low levels of alkaline phosphatase. It lacks numerous macrophage markers (lysozyme, C3, Fc receptors, and M1 antigen). The FM-2 line had a dose-dependent cyclic AMP response (7-fold increase) following treatment with calcitonin but not with parathormone. In 125I-calcitonin-binding experiments, we calculated approximately 5.3 +/- 0.2 X 10(3) receptor sites/cell with a kd of 1.8 +/- 0.1 X 10(-9) M. Conditioned medium from the FM-2 line was a potent stimulator of calcium release as assayed in a 45Ca-labeled fetal rat bone organ culture. This activity was not prostaglandin, vitamin D, parathormone, or epidermal growth factor, which are known stimulators of bone resorption. The FM-2 line does not appear to be derived from an osteoblast, macrophage, or fibroblast and may represent a calcitonin-responsive bone stem cell.
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PMID:Characteristics of a calcitonin-responsive cell line derived from a human osteosarcoma. 657 18

Mammary Paget's disease has been said to result from epidermal spread by contiguity of primary intraductal carcinoma. To assess similar identity, we immunostained Paget's cells and underlying intraductal and/or invasive mammary carcinoma in 20 cases for cytokeratins, epithelial membrane antigen, gross cystic disease fluid protein-15, lysozyme, carcinoembryonic antigen, S100 protein, kappa-casein, and alpha-lactalbumin. Steroid receptor immunostain was positive in only one (5%) of the cases of Paget's disease and in two and four (approximately 15%) (for estrogen and progesterone receptor, respectively) of the cases of ductal carcinoma. In 18 patients (90%), the immunohistochemical profile was identical in Paget's cells and associated carcinoma for seven or more antigens. In one patient, there was a definite disparity in the antigenic profile; in another patient, this was dissimilar because of very focal staining in one site. The antigenic similarity between Paget's cells and underlying carcinoma in 18 (90%) of the cases of mammary Paget's disease suggested in favor of their common origin, ie, probably intraepidermal spread of ductal carcinoma. Origin from apocrine/eccrine structures, or multipotent cells in the epidermis, was suggested in a minority.
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PMID:Mammary Paget's disease and associated carcinoma. An immunohistochemical study. 768 Jan 94

We investigated immunohistochemically the localization of lysozyme and Leu M1 in normal skin, 76 cases of benign sweat gland tumors, 28 cases of malignant sweat gland tumors, 23 cases of extramammary Paget's disease, 7 cases of sebaceous carcinoma, 6 cases of malignant trichilemmoma, 10 cases of squamous cell carcinoma, and 10 cases of basal cell carcinoma and compared the results with those for gross cystic disease fluid protein (GCDFP)-15 to assess the sensitivity and specificity of our assay conditions for apocrine differentiation. Normal apocrine glands were stained with all three antibodies, while eccrine glands were positive only for GCDFP-15, and other portions of normal skin were not stained with any of the antibodies used. In neoplastic tissue thought to be from apocrine tumors, antibodies raised against lysozyme and GCDFP-15 had a greater specificity (100%) for apocrine differentiation, while Leu M1 had a greater sensitivity (88%). Tissues that were stained with two or three of these antibodies appeared to exhibit apocrine differentiation. In the tumors examined, the specificity for apocrine differentiation was 100% and the sensitivity for such differentiation was 92% by these criteria. According to these criteria, some cases of syringocystadenoma papilliferum, primary mucinous carcinoma of the skin, and extramammary Paget's disease with underlying adenocarcinoma showed apocrine differentiation.
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PMID:An immunohistochemical study of lysozyme, CD-15 (Leu M1), and gross cystic disease fluid protein-15 in various skin tumors. Assessment of the specificity and sensitivity of markers of apocrine differentiation. 859 33

Electrostatic interactions play a key role in many aspects of protein engineering. Consequently, much effort has been put into the design of software for calculating electrostatic fields around macromolecules. We show that optimization of hydrogen bonding networks can improve both the results of pK(a) calculations and the results of electrostatic calculations performed by commonly used programs such as DelPhi. Further optimization can often be achieved by flipping the side chains of asparagine, histidine and glutamine around their chi2, chi2 and chi3 torsion angles, respectively, when this improves the local hydrogen bonding network. These optimizations are applied to some well characterized proteins: BPTI, hen egg white lysozyme and superoxide dismutase. A search for flipped residues in the PDB revealed that significant improvements in electrostatic calculations in or near the active site of enzymes can be expected for about one quarter of all enzymes in the PDB.
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PMID:Improving macromolecular electrostatics calculations. 1046 26

In order to address the recognition mechanism of the fragments of antibody variable regions, termed Fv, toward their target antigen, an x-ray crystal structure of an anti-hen egg white lysozyme antibody (HyHEL-10) Fv fragment complexed with its cognate antigen, hen egg white lysozyme (HEL), was solved at 2.3 A. The overall structure of the complex is similar to that reported in a previous article dealing with the Fab fragment-HEL complex (PDB ID code,). However, the areas of Fv covered by HEL upon complex formation increased by about 100 A(2) in comparison with the Fab-HEL complex, and two local structural differences were observed in the heavy chain of the variable region (VH). In addition, small but significant local structural changes were observed in the antigen, HEL. The x-ray data permitted the identification of two water molecules between the VH and HEL and six water molecules retained in the interface between the antigen and the light chain complementarity determining regions (CDRs) 2 and 3 (CDR-L2 and CDR-L3). These water molecules bridge the antigen-antibody interface through hydrogen bond formation in the VL-HEL interface. Eleven water molecules were found to complete the imperfect VH-VL interface, suggesting that solvent molecules mediate the stabilization of interaction between variable regions. These results suggest that the unfavorable effect of deletion of constant regions on the antigen-antibody interaction is compensated by an increase in favorable interactions, including structural changes in the antigen-antibody interface and solvent-mediated hydrogen bond formation upon complex formation, which may lead to a minimum decreased affinity of the antibody Fv fragment toward its antigen.
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PMID:Crystal structure of anti-Hen egg white lysozyme antibody (HyHEL-10) Fv-antigen complex. Local structural changes in the protein antigen and water-mediated interactions of Fv-antigen and light chain-heavy chain interfaces. 1048 2

We report 2 cases of cutaneous apocrine ductal carcinoma (CADC) of the axilla in a 64- and a 54-year-old male. Histological examination revealed 2 solid, ductal and glandular tumors with decapitation secretion. Tumor cells showed cellular and nuclear atypism, and infiltrative growth of tumor cell nests was also observed. Although there were no characteristic features of extramammary Paget's disease on the overlying skin, case 1 exhibited a typical Paget's phenomenon. We concluded that the Paget's phenomenon of case 1 was a result of upward extension of the tumor in the dermis. The neoplastic cells of both cases were immunohistochemically positive for gross cystic disease fluid protein, lysozyme, CD15 and carcinoembryonic antigen but negative for S-100 protein. Based on these findings, we concluded that these tumors were cutaneous apocrine ductal carcinomas. There was no evidence of tumor remnants in the axilla, and the patients have shown no signs of local recurrence or metastasis. We also reviewed the literature and summarize here the clinical features of CADC.
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PMID:Two cases of cutaneous apocrine ductal carcinoma of the axilla. Case report and review of the literature. 1064 Aug 44

AmpD is a bacterial amidase involved in the recycling of cell-wall fragments in Gram-negative bacteria. Inactivation of AmpD leads to derepression of beta-lactamase expression, presenting a major pathway for the acquisition of constitutive antibiotic resistance. Here, we report the NMR structure of AmpD from Citrobacter freundii (PDB accession code 1J3G). A deep substrate-binding pocket explains the observed specificity for low molecular mass substrates. The fold is related to that of bacteriophage T7 lysozyme. Both proteins bind zinc at a conserved site and require zinc for amidase activity, although the enzymatic mechanism seems to differ in detail. The structure-based sequence alignment identifies conserved features that are also conserved in the eukaryotic peptidoglycan recognition protein (PGRP) domains, including the zinc-coordination site in several of them. PGRP domains thus belong to the same fold family and, where zinc-binding residues are conserved, may have amidase activity. This hypothesis is supported by the observation that human serum N-acetylmuramyl-L-alanine amidase seems to be identical with a soluble form of human PGRP-L.
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PMID:NMR structure of Citrobacter freundii AmpD, comparison with bacteriophage T7 lysozyme and homology with PGRP domains. 1265 66

The crystal structure of the complex of the antibody Fab, HyHEL-5, with its antigen, hen egg-white lysozyme, has been refined at 2.65 A resolution to an R value of 0.196. The resulting model has significantly better stereochemistry than the previously reported model of the complex, PDB reference 2HFL, and sufficiently improved phases, permitting the reliable location of a number of water molecules. No major conformational differences are observed between this structure and that previously reported, although small differences occur throughout the complex. 82 water molecules have been assigned, of which three are in the antibody-antigen interface involved in a hydrogen-bonding network. Three other waters are trapped within the interface between V(H) and V(L) and a fourth water molecule is observed near the interface but buried below the lysozyme surface as observed in crystal structures of lysozyme alone.
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PMID:Refined structure of the monoclonal antibody HyHEL-5 with its antigen hen egg-white lysozyme. 1529 4

The structure of hexagonal turkey egg-white lysozyme (TEWL) has been determined and refined at 1.65 A resolution. The crystals were grown from a 150 mM potassium thiocyanate solution at pH 4.5 and belong to space group P6(1)22 with unit-cell dimensions a = b = 70.96, c = 83.01 A alpha = beta = 90, gamma = 120 degrees. The crystals were isomorphous with those of hexagonal pH 8.0 TEWL. The coordinates of PDB entry code 3LZ2 were therefore used as the initial model and subjected to rigid-body refinement, simulated annealing and least-squares refinement to a final residual of 0.20. The root-mean-square deviations from the ideal bond distances and angles were 0.016 A and 2.2 degrees, respectively. During the refinement, 86 water molecules and one thiocyanate ion were located in the structure. The thiocyanate ion lies close to the interface between two symmetry-related molecules. The S atom of the ion forms two direct intermolecular contacts with Argl4 and interacts indirectly via a network of water molecules to Arg5 of a symmetry-related molecule. The structure provides direct evidence for the mode of thiocyanate binding to arginine residues and suggests a possible mechanism for the efficiency of thiocyanate in crystallizing basic proteins.
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PMID:Structure of hexagonal turkey egg-white lysozyme at 1.65A resolution. 1529 95


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