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

---

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

To examine the transport of the single subunits of the glycoprotein complex gp80 (clusterin, apolipoprotein J), a marker protein for apical exocytosis and main secretory product of Madin-Darby canine kidney (MDCK) cells, several mutant cDNAs were constructed and expressed in the fibroblastic baby hamster kidney (BHK-21) cell line. In the absence of the second subunit the mutant proteins formed disulfide-linked homodimeric complexes. In the homodimeric form lys-gp45, a lysozyme-tagged mutant representing the C-terminal subunit, acquired competence for transport to the cell surface. Biogenesis and transport of this hybrid protein were also examined in stably transfected MDCK cells. In these cells which express both the endogenous gene and the mutant cDNA lys-gp45 was linked via disulfide bonds to the gp80 complex. These heterooligomeric complexes were secreted predominantly at the apical cell surface. Thus, oligomerization regardless of whether it resulted in homodimeric or heterooligomeric complexes conveyed transport competence to the mutant protein.
...
PMID:Oligomerization supports transport of a mutant secretory protein out of the endoplasmic reticulum. 890 10

Diabetic uremic sera contain excessive amounts of reactive advanced glycation endproducts (AGEs), which accelerate the vasculopathy of diabetes and end-stage renal disease. To capture in vivo-derived toxic AGEs, high affinity AGE-binding protein lysozyme (LZ) was linked to a Sepharose 4B matrix. Initial studies showed that > 80% of 125I-AGE-BSA was retained by the LZ matrix, compared with < 10% retained by a control matrix. More than 60% of AGE-lysine was captured by the LZ matrix, and the LZ-bound fraction retained immunoreactivity and cross-linking activity, but had little intrinsic fluorescence (370/440 nm). After passage through the LZ matrix, AGE levels in diabetic sera (0.37+/-0.04 U/mg) were significantly reduced to a level (0.09+/-0.01 U/mg; n = 10; P < 0. 0001) comparable with the level of normal human serum, whereas total protein absorption was < 3%. The AGE-enriched serum fraction exhibited cross-linking activity, which was completely prevented by aminoguanidine. Among numerous LZ-bound proteins in diabetic uremic sera, three major proteins "susceptible" to AGE modification were identified: the immunoglobulin G light chain, apolipoprotein J (clusterin/SP-40,40), and the complement 3b beta chain. These findings indicate that the LZ-linked AGE affinity column may serve as an efficient method for the depletion of toxic AGEs from sera, including specific AGE-modified proteins that may be linked to altered immunity, lipoprotein metabolism, and accelerated vasculopathy in renal failure patients with or without diabetes.
...
PMID:Depletion of reactive advanced glycation endproducts from diabetic uremic sera using a lysozyme-linked matrix. 925 84

After cessation of lactation, the mammary gland undergoes involution, regressing to a state resembling that of a virgin animal. This phase of mammary gland development is characterized by epithelial cell death and tissue remodeling. To understand molecular mechanisms of mammary gland involution, we identified involution-induced clones by differential screening of a mouse mammary gland cDNA library. Several known genes were induced during mammary gland involution: sulfated glycoprotein-2 (SGP-2), WDNM1, lactoferrin, ferritin heavy chain (FHC), lysozyme and osteopontin genes. Involution of the mammary gland is presumed to be mediated by a decrease in serum prolactin level induced by weaning, but may also involve changes in paracrine or autocrine growth factors. Effects of lactogenic hormones and EGF on the expression of the involution-induced genes were examined in mammary epithelial cells. Insulin, dexamethasone, and prolactin did not influence the expression of the FHC, WDNM1 and SGP-2 genes. However, EGF strongly inhibited the expression of WDNM1 and SGP-2 genes. Our recent results are reviewed and discussed.
...
PMID:Gene expression during involution of mammary gland (review). 985 40

Clusterin is an extracellular mammalian chaperone protein which inhibits stress-induced precipitation of many different proteins. The conformational state(s) of proteins that interact with clusterin and the stage(s) along the folding and off-folding (precipitation-bound) pathways where this interaction occurs were previously unknown. We investigated this by examining the interactions of clusterin with different structural forms of alpha-lactalbumin, gamma-crystallin and lysozyme. When assessed by ELISA and native gel electrophoresis, clusterin did not bind to various stable, intermediately folded states of alpha-lactalbumin nor to the native form of this protein, but did bind to and inhibit the slow precipitation of reduced alpha-lactalbumin. Reduction-induced changes in the conformation of alpha-lactalbumin, in the absence and presence of clusterin, were monitored by real-time (1)H NMR spectroscopy. In the absence of clusterin, an intermediately folded form of alpha-lactalbumin, with some secondary structure but lacking tertiary structure, aggregated and precipitated. In the presence of clusterin, this form of alpha-lactalbumin was stabilised in a non-aggregated state, possibly via transient interactions with clusterin prior to complexation. Additional experiments demonstrated that clusterin potently inhibited the slow precipitation, but did not inhibit the rapid precipitation, of lysozyme and gamma-crystallin induced by different stresses. These results suggest that clusterin interacts with and stabilises slowly aggregating proteins but is unable to stabilise rapidly aggregating proteins. Collectively, our results suggest that during its chaperone action, clusterin preferentially recognises partly folded protein intermediates that are slowly aggregating whilst venturing along their irreversible off-folding pathway towards a precipitated protein.
...
PMID:Clusterin is an extracellular chaperone that specifically interacts with slowly aggregating proteins on their off-folding pathway. 1190 61

We have studied the effects of the extracellular molecular chaperone, clusterin, on the in vitro aggregation of mutational variants of human lysozyme, including one associated with familial amyloid disease. The aggregation of the amyloidogenic variant I56T is inhibited significantly at clusterin to lysozyme ratios as low as 1:80 (i.e. one clusterin molecule per 80 lysozyme molecules). Experiments indicate that under the conditions where inhibition of aggregation occurs, clusterin does not bind detectably to the native or fibrillar states of lysozyme, or to the monomeric transient intermediate known to be a key species in the aggregation reaction. Rather, it seems to interact with oligomeric species that are present at low concentrations during the lag (nucleation) phase of the aggregation reaction. This behavior suggests that clusterin, and perhaps other extracellular chaperones, could have a key role in curtailing the potentially pathogenic effects of the misfolding and aggregation of proteins that, like lysozyme, are secreted into the extracellular environment.
...
PMID:The extracellular chaperone clusterin potently inhibits human lysozyme amyloid formation by interacting with prefibrillar species. 1740 82

The organic components of bones and other mineralized tissues have a high impact on the organization and deposition of calcium, and consequently influence the mechanical properties of those tissues. The extractable proteins of avian eggshells have been studied extensively and many of them have been identified; insoluble (non-extractable) proteins have been sparsely studied, however. In the work discussed in this paper we studied EDTA-insoluble proteins by gradual decalcification of eggshell with EDTA. The insoluble proteinaceous films were chemically treated with cyanogen bromide and the mixtures of large fragments obtained were gradually precipitated with salt. The separated fractions were digested with trypsin and analyzed by HPLC-MS-MS (ion trap mass spectrometer). Analysis of the entire eggshell matrix (without precipitation steps) only enabled 6 proteins to be determined (ovocalyxins 32 and 36, ovocleidin 17 and 116, clusterin, and ovalbumin). Pretreatment of the individual eggshell layers and gradual precipitation with salt markedly increased the number of proteins identified - 28 proteins were determined. We identified for the first time collagens I (two chains) and III in the eggshell matrix, and Kunitz-like protease inhibitor as a major shell matrix protein. Besides the above mentioned proteins we can also mention EDIL3, fibronectin, sulfhydryl oxidase, tubulin alpha 1, lysozyme, Dickkopf-related protein 3, keratins, and ovotransferrin. The relative abundances of proteins in all eggshell layers were determined using the exponentially modified protein abundance index (emPAI). In the cuticle layer seven proteins were identified, whereas 16 proteins were described in the palisade layer and 23 in the mammillary layer.
...
PMID:Determination of insoluble avian eggshell matrix proteins. 1999 26

Whey and casein proteins representing the first and second halves of the early lactation phase in the common brushtail possum (Trichosurus vulpecula) have been compared by two dimensional gel electrophoresis. Nine components of whey were differentially expressed during early lactation, including proteins identified as cathepsin B, clusterin, late lactation protein, lysozyme, ganglioside M2 activator and neutrophil gelatinase-associated lipocalin. A major novel protein, termed very early lactation protein (VELP), was identified in whey. Partial amino acid sequence data obtained from VELP did not appear to match any other reported protein sequence. VELP was shown to be an acidic glycoprotein of 20-30 kDa which exists as a homodimer. In the casein fraction, kappa-casein appeared to be differentially post-translationally modified during early lactation and fragments of beta-casein were relatively more abundant at the earlier lactation stage.
...
PMID:Proteomic analysis of whey and casein proteins in early milk from the marsupial Trichosurus vulpecula, the common brushtail possum. 2048 84

Hen egg white comprises of a complex mixture of proteins, which greatly differ in their physicochemical characteristics and relative abundance. We aimed to identify potential undiscovered egg allergens within the egg white proteome and investigated the existence of matrix effects on the proteolytic stability and resultant IgE-binding of the allergenic proteins. In addition to the main egg allergens: ovalbumin (OVA), ovomucoid (OM) and lysozyme (LYS), two minor egg white proteins, tentatively identified as ovoinhibitor and clusterin, were found to react with serum IgE from egg-allergic patients. Egg white exhibited residual immunoreactivity after gastrointestinal digestion due to the presence of intact OVA and LYS, as well as of several IgE-binding peptides derived from OVA. The presence of egg yolk slightly increased the susceptibility to hydrolysis of egg white proteins and abrogated bile salt-induced precipitation of LYS in the duodenal medium. However, the resultant immunoreactivity against IgE of egg white proteins after in vitro digestion was not significantly modified by the presence of yolk components.
...
PMID:Immunoreactivity of hen egg allergens: influence on in vitro gastrointestinal digestion of the presence of other egg white proteins and of egg yolk. 2312 26

In-depth studies on the proteome of reflex tears are still inadequate. Hence, further studies on this subject will unravel the key proteins which are conjectured to possess vital functions in the protection of the ocular surface. Therefore, this study investigated the differences in the expression levels in proteome of reflex compared to basal tears. Basal (n = 10) and reflex (n = 10) tear samples from healthy subjects were collected employing the capillary method, subsequently pooled and the proteomes were characterized employing 1DE combined with LC-ESI-MS/MS strategy for label-free quantitative (LFQ) analysis. The differentially expressed proteins were validated by 2DE combined with LC-ESI-MS/MS and targeted-MS approach called accurate inclusion mass screening (AIMS) strategies. The analysis of the reflex tear proteome demonstrated increased abundance in proline-rich protein 4 (PRR4) and zymogen granule protein 16 homolog B (ZG16B) for the first time. Other abundant lacrimal proteins, e.g. lactotransferrin and lysozyme remained constant. Predominantly, the lacrimal gland-specific PRR4 represents the major increased protein in reflex tears in an attempt to wash out irritants that come into contact with the eye. Conversely, decreased abundance in Ig alpha-1 chain C, polymeric immunoglobulin receptor, cystatin S/SN, clusterin and mammaglobin were observed. This study had further unraveled the intricate proteome regulation during reflex tearing, especially the potential role of PRR4, which may be the key player in the protection and maintenance of dynamic balance of the ocular surface.
...
PMID:Characterization of human reflex tear proteome reveals high expression of lacrimal proline-rich protein 4 (PRR4). 2617 77

Egg shells are poultry industry byproducts with potential for use in various biological and agricultural applications. We have been interested in the membranes underlying the calcareous shell as a feed supplement, which showed potential to improve immunity and performance of post hatch poultry. Therefore, to determine their protein and peptide profiles, we extracted the egg shell membranes (ESM) from fresh unfertilized eggs with methanol and guanidine hydrochloride (GdHCl) to obtain soluble proteins for analysis by mass spectrometry. The methanol extract was subjected to matrix-assisted laser desorption ionization (MALDI), electrospray ionization (ESI), high-performance reverse phase liquid chromatographic separation (HPLC), and tandem mass spectrometry (MS/MS) to determine its peptide and protein profiles. The GdHCl extract was subjected to ESI-HPLC-MS/MS following trypsin digestion of reduced/alkylated proteins. Nine proteins from the methanol extract and >275 proteins from the GdHCl extract were tentatively identified. The results suggested the presence of several abundant proteins from egg whites, such as ovoalbumin, ovotransferrin, and lysozyme as well as many others associated with antimicrobial, biomechanical, cytoskeletal organizational, cell signaling, and enzyme activities. Collagens, keratin, agrin, and laminin were some of the structural proteins present in the ESM. The methanol-soluble fraction contained several clusterin peptides and defensins, particularly, two isoforms of gallin. The ratios of the two isoforms of gallin differed between the membranes obtained from brown and white eggs. The high abundance of several antimicrobial, immunomodulatory, and other bioactive proteins in the ESM along with its potential to entrap various microbes and antigens may make it a suitable vehicle for oral immunization of post hatch poultry and improve their disease resistance.
...
PMID:Chicken Egg Shell Membrane Associated Proteins and Peptides. 2648 61


1

---