Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The yeast Saccharomyces cerevisiae processes N-linked glycans in the Golgi apparatus in two different ways. Whereas most of the proteins of internal membranes receive a simple core-type structure, a long branched polymer termed mannan is attached to the glycans of many of the proteins destined for the cell wall. The first step in mannan synthesis is the initiation and extension of an alpha-1,6-linked polymannose backbone. This requires the sequential action of two enzyme complexes, mannan polymerases (M-Pol) I and II. M-Pol I contains the proteins Mnn9p and Van1p, although the stoichiometry and individual contributions to enzyme action are unclear. We report here that the two proteins are each present as a single copy in the complex. Both proteins contain a DXD motif found in the active site of many glycosyltransferases, and mutations in this motif in Mnn9p or Van1p reveal that both proteins contribute to mannose polymerization. However, the effects of these mutations on both the in vivo and in vitro activity are distinct, suggesting that the two proteins may have different roles in the complex. Finally, we show that a simple glycoprotein based on hen egg lysozyme can be used as a substrate for modification by purified M-Pol I in vitro.
 ...
PMID:The components of the Saccharomyces cerevisiae mannosyltransferase complex M-Pol I have distinct functions in mannan synthesis. 1223 55

Bo-yang-hwan-o-tang (BHT) has long been used to treat cancer in traditional Korean medicine and is believed to have immune-modulating activity. This study investigated the effect of BHT on the induction of antigen-specific immune responses using hen egg-white lysozyme (HEL) as a model antigen system. Oral administration of BHT enhanced both HEL-specific humoral and lymphocyte proliferative responses in HEL low-responder mice. Feeding BHT to the mice increased INF-gamma levels, but did not change IL-4 levels. Interestingly, however, the oral BHT feeding significantly increased HEL-specific antibodies of the IgG1, IgG2b, and IgG3 subtypes, which are associated with the direct stimulation of B cells. This indicates that BHT treatment enhances anti-HEL-specific humoral immune responses via the direct stimulation of B lymphocytes rather than by selective priming of specific subtypes of the helper T-cell population. This conclusion was supported by in vitro experiments, in which the presence of BHT significantly augmented B-cell mitogen-mediated proliferation of mouse splenocytes. This augmentation was closely associated with a glycoprotein with a molecular weight of around 100 kDa. The results suggest that BHT modulates antigen-specific immune responses, and might be used as a therapeutic agent for patients who need enhanced immune function.
 ...
PMID:Modulation of antigen-specific immune responses by the oral administration of a traditional medicine, bo-yang-hwan-o-tang. 1237 38

Soamsan is a traditional anti-cancer treatment in oriental medicine. It is thought that this material modulates immune responses. To determine whether Soamsan treatment has any effect on the induction of antigen-specific immune responses, C57BL/6 mice, which are low-responders to hen egg-white lysozyme (HEL), were injected with HEL, and their specific immune responses were measured while they were fed Soamsan. Oral administration of Soamsan enhanced the anti-HEL antibody response as well as the T-cell proliferative response to the antigen. Analyses of the HEL-specific antibody isotypes showed that Soamsan treatment resulted in increased levels of HEL-specific antibodies, irrespective of isotype. In particular, however, HEL-specific antibodies of the IgG2b, IgG3, and IgM isotypes, which are associated with direct stimulation of B cells, were significantly increased by the Soamsan treatment. Stimulation of C57BL/6 splenocytes in vitro showed that the presence of Soamsan significantly augmented the proliferative activity induced by both B and T cell mitogens. This augmentation was associated with glycoprotein(s) with a molecular weight mass of about 100 kDa, as well as with endotoxin-like compounds. These results suggest that Soamsan modulates and enhances antigen-specific immune responses.
 ...
PMID:Soamsan, a traditional Korean medicine, enhances antigen-specific immune responses in low-responder mice via the combined activity of glycoproteins and endotoxins. 1243 54

Crystalline bacterial cell surface layer (S-layer) proteins are composed of a single protein or glycoprotein species. Isolated S-layer subunits frequently recrystallize into monomolecular protein lattices on various types of solid supports. For generating a functional protein lattice, a chimeric protein was constructed, which comprised the secondary cell wall polymer-binding region and the self-assembly domain of the S-layer protein SbpA from Bacillus sphaericus CCM 2177, and a single variable region of a heavy chain camel antibody (cAb-Lys3) recognizing lysozyme as antigen. For construction of the S-layer fusion protein, the 3'-end of the sequence encoding the C-terminally truncated form rSbpA(31)(-)(1068) was fused via a short linker to the 5'-end of the sequence encoding cAb-Lys3. The functionality of the fused cAb-Lys3 in the S-layer fusion protein was proved by surface plasmon resonance measurements. Dot blot assays revealed that the accessibility of the fused functional sequence for the antigen was independent of the use of soluble or assembled S-layer fusion protein. Recrystallization of the S-layer fusion protein into the square lattice structure was observed on peptidoglycan-containing sacculi of B. sphaericus CCM 2177, on polystyrene or on gold chips precoated with thiolated secondary cell wall polymer, which is the natural anchoring molecule for the S-layer protein in the bacterial cell wall. Thereby, the fused cAb-Lys3 remained located on the outer S-layer surface and accessible for lysozyme binding. Together with solid supports precoated with secondary cell wall polymers, S-layer fusion proteins comprising rSbpA(31)(-)(1068) and cAbs directed against various antigens shall be exploited for building up monomolecular functional protein lattices as required for applications in nanobiotechnology.
 ...
PMID:Generation of a functional monomolecular protein lattice consisting of an s-layer fusion protein comprising the variable domain of a camel heavy chain antibody. 1264 55

Human acquired enamel pellicle is formed by molecules selectively adsorbed onto tooth surfaces. The present work describes the use of monoclonal antibody (mAb) technology as a novel approach to identify micro amounts of components present in pellicle. MAbs were obtained with reactivities against statherin, histatin, mucous glycoprotein 1(MGI), albumin, amylase and human immunoglobulins (Igs), indicating that these are pellicle components, which was further confirmed by immunoblotting. No mAbs against proline-rich proteins (PRPs), lysozyme, mucous glycoprotein 2 (MG2), carbonic anhydrase, lactoferrin or peroxidase were obtained, suggesting that these components are absent, present in low amounts, or exhibit low antigenicity. Further characterization of the binding epitopes of some of th e obtained anti-MGO, anti-statherin and anti-histatin mAbs were carried out and the biological relevance is discussed. The results open up the possibility that immunization with human pellicle and mAbs production can be employed to identify hitherto unknown constituents of pellicle.
 ...
PMID:Characterization of the immunologic responses to human in vivo acquired enamel pellicle as a novel means to investigate its composition. 1275 71

Human acquired enamel pellicle is composed of molecules that selectively adsorb from saliva onto tooth surfaces and provides a protective interface between the tooth enamel and the oral environment. To identify the micro-amounts of components present in pellicle, we immunized mice with in vivo-formed human acquired enamel pellicle and analyzed the serum immune responses. Selective reactivities of the serum (OD > 1.0 above background) against albumin, amylase, carbonic anhydrase II, sIgA, IgG, IgM, lactoferrin, lysozyme, proline-rich proteins, statherin, histatin 1, and mucous glycoprotein 1 were observed. We further confirmed the presence of proline-rich proteins, lactoferrin, lysozyme, and carbonic anhydrase II by probing in vivo pellicle with specific polyclonal anti-sera. The polyclonal antibody approach provided a powerful method for the identification of various pellicle proteins, including some which show mineral homeostasis or antimicrobial activity.
 ...
PMID:Identification of in vivo pellicle constituents by analysis of serum immune responses. 1469 Nov 15

A 2-year-old Sprague-Dawley rat with hindlimb paralysis was diagnosed with a cerebral malignant astrocytoma. The distinctive feature of this astrocytoma was the presence of scattered binucleated cells that contained hypereosinophilic, 1-2 micro m in diameter, cytoplasmic granules. The neoplastic astrocytes stained positively for vimentin (VIM), lysozyme, and phosphotungstic acid hematoxylin (PTAH). Within the binucleated cells, granules stained with PTAH and periodic acid-Schiff (PAS) before and after diastase digestion. Ultrastructurally, neoplastic astrocytes were characterized by cytoplasmic aggregates of electron-dense intermediate filaments consistent with VIM and desmin. The cytoplasm of binucleated cells contained numerous phagolysosomes enlarged by myelin figures and glycoprotein or glycolipid. Intermediate filaments were not present. This is the first description, in the rat, of a neoplasm with features resembling the human granular cell astrocytoma. Our findings suggest that an astrocytic origin should be considered for the binucleated cells in this neoplasm.
 ...
PMID:Malignant astrocytoma with binucleated granular cells in a Sprague-Dawley rat. 1513 82

Saliva is essential for a lifelong conservation of the dentition. Various functions of saliva are implicated in the maintenance of oral health and the protection of our teeth: (i) The tooth surface is continuously protected against wear by a film of salivary mucins and proline-rich glycoprotein. (ii) The early pellicle proteins, proline-rich proteins and statherin, promote remineralization of the enamel by attracting calcium ions. (iii) Demineralization is retarded by the pellicle proteins, in concert with calcium and phosphate ions in saliva and in the plaque fluid. (iv) Several salivary (glyco)proteins prevent the adherence of oral microorganisms to the enamel pellicle and inhibit their growth. (v) The salivary bicarbonate/carbonate buffer system is responsible for rapid neutralization of acids. An overview is presented on the major antimicrobial systems in human saliva. Not only the well-known major salivary glycoproteins, including mucins, proline-rich glycoprotein and immunoglobulins, but also a number of minor salivary (glyco)proteins, including agglutinin, lactoferrin, cystatins and lysozyme, are involved in the first line of defense in the oral cavity. Besides, small cationic antimicrobial peptides, e.g. defensins, cathelicidin and the histatins, have come into focus. These are potentially suited as templates for the design of a new generation of antibiotics, since they kill a broad spectrum of microorganisms, while hardly evoking resistance, in contrast to the classical antibiotics.
 ...
PMID:Salivary proteins: protective and diagnostic value in cariology? 1515 96

Avidin, the basic biotin-binding glycoprotein from chicken egg white, is known to interact with DNA, whereas streptavidin, its neutral non-glycosylated bacterial analog, does not. In the present study we investigated the DNA-binding properties of avidin. Its affinity for DNA in the presence and absence of biotin was compared with that of other positively charged molecules, namely the protein lysozyme, the cationic polymers polylysine and polyarginine and an avidin derivative with higher isoelectric point (pI approximately 11) in which most of the lysine residues were converted to homoarginines. Gel-shift assays, transmission electron microscopy and dynamic light scattering experiments demonstrated an unexpectedly strong interaction between avidin and DNA. The most pronounced gel-shift retardation occurred with the avidin-biotin complex, followed by avidin alone and then guanidylated avidin. Furthermore, ultrastructural and light-scattering studies showed that avidin assembles on the DNA molecule in an organized manner. The assembly leads to the formation of nanoparticles that are about 50-100 nm in size (DNA approximately 5 kb) and have a rod-like or toroidal shape. In these particles the DNA is highly condensed and one avidin is bound to each 18 +/- 4 DNA base pairs. The complexes are very stable even at high dilution ([DNA] =10 pM) and are not disrupted in the presence of buffers or salt (up to 200 mM NaCl). The other positively charged molecules also condense DNA and form particles with a globular shape. However, in this case, these particles disassemble by dilution or in the presence of low salt concentration. The results indicate that the interaction of avidin with DNA may also occur under physiological conditions, further enhanced by the presence of biotin. This DNA-binding property of avidin may thus shed light on a potentially new physiological role for the protein in its natural environment.
 ...
PMID:DNA condensation by high-affinity interaction with avidin. 1538 19

The interactions of hydroxypropyl guar (HPG) with boric acid, lysozyme, and mucin were characterized by rheology, light scattering, electrophoresis, and isothermal titration calorimetry to help understand how HPG interacts with tear film components. Borate binds to guar under pH, temperature, and ionic strength conditions representative of those found in the eye. The HPG-borate complexes behave as anionic polyelectrolytes and thus interact with cationic lysozyme, a major tear film protein, whereas HPG-borate does not appear to bind to mucin, an anionic glycoprotein. The interactions of HPG, borate, lysozyme, and mucin can be explained by two physical interactions: (1) pH-dependent binding of borate to carbohydrates and (2) the electrostatic attraction of oppositely charged macromolecules.
 ...
PMID:Hydroxypropyl guar-borate interactions with tear film mucin and lysozyme. 1622 24


<< Previous 1 2 3 4 5 6 7 8 9 10