Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.36 (hyaluronidase)
 4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A protein toxic to mice was isolated from the venom of the Mexican beaded lizard Heloderma horridum horridum by a combination of gel filtration (Sephadex G-75) and ion exchange chromatography (both diethylaminoethyl-cellulose [DE-cellulose] and carboxymethyl-cellulose [CM-cellulose]). The purified polypeptide component has an apparent mol. wt of 25,500 and is composed of approximately 220 amino acid residues. It has an isoelectric point (pI) of 6.8 and its N-terminal amino acid sequence was shown to be: Glu-Ala-Ser-Pro-Lys-Leu-Pro-Gly-Leu-Met-Thr-Ser-Asn-Pro-Asp-Gln-Gln-Thr- Glu-Ile. The sequence has no significant similarity with any other protein previously reported in the literature. Enzymatic activities such as phospholipase, hyaluronidase and proteinase, commonly present in venoms, could not be demonstrated in this protein. Patch-clamp experiments conducted with excitable membranes show no effects on Na+, K+ or Ca2+ ion channels. Among the constant physiological effects observed in mice injected with this toxin are lethargy, partial paralysis of rear limbs and lowering of body temperature, suggesting that it might be a hypothermic toxin. We propose calling this toxin Helothermine.
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PMID:Isolation and characterization of helothermine, a novel toxin from Heloderma horridum horridum (Mexican beaded lizard) venom. 169 19

The venom from Crotalus molossus nigrescens contains many activities including: hyde powder azure proteinase; N-benzoyl-arginine-ethyl-ester hydrolase; phospholipase; phosphodiesterase; desoxyribonuclease; fibrinogen coagulase; collagenase, fibrinolytic activity, and hemorrhagic factors. The venom, assayed with amounts of venom up to 50 micrograms protein per assay, does not contain acetylcholinesterase, phosphatase, amylase, ribonuclease, tyrosyl-ester hydrolase or hyaluronidase activities. The venom is lethal to mice with an i.p. LD50 of 2.35 mg/kg mouse. Fractionation of soluble venom by Sephadex G-75 separates at least five families of components. Fractions I-III contains all the enzymes, and fraction V have six small peptides. Further separation of fractions II-III on diethyl-amino-ethyl-cellulose columns at pH 8.0 and 8.3 gave pure proteinase E with a mol. wt of 21,390 and the following N-terminal amino acid sequence; Phe-Ala-Lys-Arg-Tyr-Val-Glx-Leu-Val-Ile-Val-Ala. A thrombin-like enzyme with a mol. wt of 75,000 was also purified from this venom by means of affinity and ion exchange chromatographies.
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PMID:Characterization of the venom from Crotalus molossus nigrescens Gloyd (black tail rattlesnake): isolation of two proteases. 218 98

The distinction between malignant epithelioid pleural mesothelioma (MEPM) and peripheral adenocarcinoma of the lung with pleural invasion (PAL) continues to represent a diagnostic challenge in selected cases. In order to provide comparative data on histologic, histochemical, and immunohistochemical features of these neoplasms, we analyzed 51 ultrastructurally categorized MEPMs and 52 PALs with the periodic acid-Schiff-diastase (PAS-D), mucicarmine, and colloidal iron stains, and a panel of immunohistologic reagents. Antibodies to cytokeratin, vimentin, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), Leu M1, the B72.3 antigen, blood group isoantigens (BGI), placental alkaline phosphatase, amylase, S100 protein, and Clara cell antigen were used, as applied to paraffin sections with the avidin-biotin-peroxidase complex technique. Ultrastructural studies revealed long, branching microvilli in MEPM cells in all cases, with length-to-diameter ratios (LDR) of 10:1 or more. In contrast, PAL manifested short, nonbranching microvilli with LDR of 8:1 or less. Reactivity with PAS-D and mucicarmine stains was strictly confined to PAL, and hyaluronidase-sensitive colloidal iron-positivity was restricted to MEPM. However, only 63% and 41% of these respective neoplasms demonstrated such histochemical reactivity. Immunohistologic results correlated well with electron microscopic classification. All MEPMs and PALs were reactive for cytokeratin; in addition, the majority of tumors in each group expressed EMA, and a minority were reactive for vimentin. In adenocarcinomas of the lung, Leu M1 was observed in all cases, CEA was apparent in 96%, B72.3 labeled 84%, and BGI were present in 67%; all PALs expressed at least two of these determinants, but none was seen in any mesothelioma. The other markers included in this study also were observed in some PAL cases, but not in MEPM. These findings suggest that immunohistology parallels electron microscopy in efficacy in the diagnostic separation of MEPM and PAL. Using antibodies to Leu M1, CEA, and the B72.3 antigen, reactivity for at least two of these three markers appears to exclude a diagnosis of pleural mesothelioma. The other glycoproteinaceous, oncoplacentofetal, and cytoplasmic antigens we studied can be used to reinforce such a determination, since their distribution is confined to adenocarcinomas.
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PMID:Malignant epithelioid pleural mesothelioma versus peripheral pulmonary adenocarcinoma: a histochemical, ultrastructural, and immunohistologic study of 103 cases. 219 75

A case of a malignant mesothelioma of the tunica vaginalis is presented. The patient with an intrascrotal mass was a 32-year-old Japanese male who had no history of asbestos exposure. The tumor was located on the surface of the right testis and was composed of columnar to polygonal cells with glandular and papillary structures. It showed many mitoses and focal invasion of the tunica albuginea. The tumor cells contained alcian blue- and Hale's colloidal iron-positive, hyaluronidase-digestible materials. Immunohistochemical stains for cytokeratin and vimentin were positive, while those for carcinoembryonic antigen, epithelial membrane antigen, Leu-M1, and factor VIII-related antigen were negative. The systemic examinations revealed no other tumors. Based on these findings the tumor was diagnosed as malignant mesothelioma of the tunica vaginalis. The differential diagnosis is discussed under the histologic, histochemical, and immunohistochemical points of view and the previous literature is reviewed.
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PMID:Malignant mesothelioma of the tunica vaginalis. 228 93

The immunoreactivity of five antibodies was evaluated on six routinely processed mesotheliomas to evaluate their ability to distinguish mesothelioma from metastatic adenocarcinoma. The diagnosis in all cases was confirmed by electron microscopic examination and histochemical stains for neutral mucin (periodic acid-Schiff-diastase) and acid mucin (alcian blue with and without hyaluronidase). AE1, a monoclonal antikeratin antibody that stains most carcinomas, reacted with all six cases of mesothelioma. HMFG-2 and anti-epithelial membrane antigen (antibodies reactive with human milk fat globule proteins), two other closely related antibodies reactive with most carcinomas, also reacted with all of the mesotheliomas in the authors' series. A polyclonal antibody to carcinoembryonic antigen (anti-CEA) did not stain any of the mesotheliomas in their series. Anti-Leu-M1 did not react with the mesotheliomas. The authors conclude that none of these antibodies, when used alone on routinely fixed paraffin-embedded material, is both sensitive and specific in the distinction of mesothelioma from adenocarcinoma. However, immunoperoxidase studies using anti-CEA and anti-Leu-M1 may occasionally be helpful when used in conjunction with other histochemical stains and electron microscopic examination in distinguishing mesothelioma from metastatic adenocarcinoma.
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PMID:Immunohistochemical staining in malignant mesotheliomas. 244 94

Primary cultures of rabbit articular chondrocytes have been maintained for 10 days and labeled with [35S]sulfate, [3H]leucine, and [35S]cysteine in pulse-chase protocols to study the structure and hyaluronate binding properties of newly synthesized proteoglycan monomers. Radiolabeled monomers were purified from medium and cell-layer fractions by dissociative CsCl gradient centrifugation with bovine carrier monomer, and analyzed for hyaluronate binding affinity on Sepharose CL-2B in 0.5 M Na acetate, 0.1% Triton X-100, pH 6.8. Detergent was necessary to prevent self-association of newly synthesized monomers during chromatography. Monomers secreted during a 30-min pulse labeling with [35S]sulfate had a low affinity relative to carrier. Those molecules released into the medium during the first 12 h of chase (about 40% of the total) remained in the low affinity form whereas those retained by the cell layer rapidly acquired high affinity. In cultures where more than 90% of the preformed cell-layer proteoglycan was removed by hyaluronidase digestion before radiolabeling the newly synthesized low affinity monomers also rapidly acquired high affinity if retained in the cell layer. Cultures labeled with amino acid precursors were used to establish the purity of monomer preparations and to isolate core proteins for study. Leucine- or cysteine-labeled core proteins derived from either low or high affinity monomer preparations migrated as a single major species on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with electrophoretic mobility very similar to that of core protein derived from extracted proteoglycan monomer. Purified low affinity monomers were converted to the high affinity form by treatment at pH 8.6; however, this change was prevented by guanidinium-HCl at concentrations above 0.8 M. Conversion to high affinity was also achieved by incubation of monomers in aggregate with hyaluronic acid (HA) at pH 6.8 followed by dissociative reisolation of monomer. At both pH 6.8 and 8.6 the conversion process was slow, requiring up to 48 h for the maximum increase in affinity. It is suggested that the slow increase in HA binding affinity seen during extracellular processing of proteoglycans in cartilage and chondrocyte cultures is the result of an irreversible structural change in the HA binding domain following the binding of monomer to hyaluronate. The available evidence suggests that this change involves the formation or rearrangement of disulfide bonds.
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PMID:Studies on the hyaluronate binding properties of newly synthesized proteoglycans purified from articular chondrocyte cultures. 249 59

Pro-inflammatory effects of cationic proteins secreted by human granulocytes include induction of increased vascular permeability and oedema, which are likely to be mediated by damage to vascular endothelium. We have shown previously that a series of synthetic polycationic amino acids produce a dose-, time- and Mr-dependent inhibition of [3H]leucine or [3H]thymidine incorporation into macromolecules by human umbilical vein endothelial cells, and that the extent of inhibition was correlated with changes in cell morphology, with release of cytoplasmic constituents and was irreversible. The experiments reported here characterise further the requirements for the induction of cytotoxicity by polycations. We have found that the extent of inhibition is related to both the identity of the monomer, for polymers of Mr 40,000 the order is ornithine greater than lysine greater than arginine, and to its configuration; poly-D-lysines are more potent inhibitors than poly-L-lysines of similar Mr. Only brief exposure to the agonist is required, 90% inhibition occurred after 10 min of exposure to poly-L-lysine (Mr 90,000). Treatment of endothelial cells with neuraminidase, heparinase, hyaluronidase, chondroitinase or trypsin did not reduce their susceptibility to polylysine. Inhibition of microtubule or microfilament formation also had no effect on polylysine cytotoxicity, indicating that internalisation of the polymer was not a prerequisite for the effect. Inhibition of protein synthesis or pretreatment with simple sugars likewise failed to block the effects of polylysine treatment. Natural cationic proteins exerted similar effects on endothelial cells, the extent of the effect apparently being related to the pI of the protein.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Biochemical characterisation of polycation-induced cytotoxicity to human vascular endothelial cells. 263 82

The immunohistochemical reactivity of 38 mesotheliomas and 44 adeno-carcinomas or large cell carcinomas of the lung with monoclonal antibodies (MAb) B72.3 and Leu M1 was compared with their reactivity with the routine histochemic stains periodic acid-Schiff with diastase digestion (PAS-D) and alcian blue +/- hyaluronidase. Both MAbs reacted selectively with carcinomas when a positive test was set at greater than or equal to 10% reactive tumor cells. However, MAb B72.3 reacted with significantly more of the carcinomas (86%, chi-square test, P less than 0.01) and bound to a greater percentage of tumor cells (47 +/- 28%; mean +/- SD, t-test, P less than 0.001) than Leu M1 (57% and 25 +/- 28%, respectively). The similar reactivities of surgically resected tumor specimens and post mortem tissues with both antibodies confirmed antigen stability and suggested broad clinical utility. PAS-D stained 61% of the carcinomas. Using the markers for carcinomas (PAS-D, B72.3, and Leu M1), the tumors were classified into the correct group in 80 of 82 (98%) cases (95% confidence level: greater than 92% accuracy). The alcian blue stain was useful to confirm a diagnosis of dimorphic or epithelial mesothelioma (48% were positive).
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PMID:Differentiation of adenocarcinoma of the lung from mesothelioma. Periodic acid-Schiff, monoclonal antibodies B72.3, and Leu M1. 284 90

The incorporation of labeled acetate into lipids was studied in rat hepatocytes isolated after treatment of liver with collagenase and hyaluronidase. About 60% of the lipid radioactivity was in free cholesterol and 13% was in triglycerides. Acetate incorporation was markedly inhibited when human serum lipoproteins were present in the incubation medium. Very low, high, and low density lipoproteins, at concentrations of 1.0 mg/ml, inhibited acetate incorporation by 70, 55, and 35%, respectively. Chylomicrons, at similar concentrations, did not inhibit acetate incorporation. The distribution of radioactivity into lipid classes was unchanged by the addition of lipoproteins. Lipoproteins did not produce a nonspecific toxic effect on hepatocytes, since their addition did not alter the rate of leucine incorporation into protein. The addition of the delipidated protein from low density lipoprotein or of lecithin in amounts comparable to those present in inhibitory concentrations of lipoproteins failed to diminish acetate incorporation. Artificial cholesterol-lecithin emulsions containing small amounts of free cholesterol did not inhibit lipid synthesis. Although the mechanism for the inhibition of acetate incorporation by lipoproteins is unclear, such effects may play some physiological role in the control of lipid biosynthesis in the liver.
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PMID:Inhibition of lipid synthesis in isolated rat hepatocytes by serum lipoproteins. 433 Sep 26

Certain strains of Moraxella bovis produce tissue-damaging enzymes which may initiate or potentiate infectious bovine keratoconjunctivitis. Thirteen reference strains of this species were characterized physiologically and screened for production of various enzymes by some conventional biochemical tests and the API ZYM system (Analytab Products, Plainview, N.Y.). All 13 strains were hemolytic. All hydrolyzed Tween 80 and Tween 85 and displayed C4 esterase, C8 esterase-lipase, and C14 lipase activities. All produced phosphoamidase and phosphatase. All were able to hydrolyze casein and gelatin. All produced leucine and valine aminopeptidases and fibrinolysin. Twelve produced hyaluronidase or were agarolytic. Three hydrolyzed chondroitin sulfate. Nine strains autoagglutinated. Five produced catalase, and two produced cystine aminopeptidase.
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PMID:Hydrolytic enzymes of Moraxella bovis. 625 99


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