Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.3.13 (lysyl oxidase)
 1,248 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lysyl oxidase activity of human normal skins derived from the frontal thighs of 33 subjects showed large variations and the mean value was 11 455 +/- 7 172 (S.D.) cpm/g of wet weight tissue. The age of lesion affected the lysyl oxidase activity in postburn scars. Granulation tissues showed a fairly low activity; however, the activity increased sharply within 2--3 months, and reached a significantly higher value than that of normal skin. The high level of activity continued for up to 2--3 years, then gradually decreased to normal range after 5 years or so. Lysyl oxidase activity was detected only after 4 M urea treatment of tissues. Benzylamine oxidase activity also showed large variations in both normal skins and postburn scars, with mean values of: 0.128 +/- 0.077 (S.D.) and 0.145 +/- 0.090 (S.D.) mmol/g of wet weight/h, respectively. No correlation was observed between lysyl oxidase and benzylamine oxidase activities. The granulation tissues showed significantly high values of benzylamine oxidase activity in contrast to the low values of lysyl oxidase activity.
 ...
PMID:Lysyl oxidase activity in human normal skins and postburn scars. 0 13

Lysyl oxidase had been purified to near homogeneity from bovine aorta and bovine ligamentum nuchae employing a modification of methods described by Harris et al., and Stassen and his colleagues. The aortic enzyme gives rise to at least three peaks and the ligament enzyme resolves into at least four peaks upon chromatography on DEAE cellulose. The molecular weight of each peak of both enzymes is approximately 30,000 daltons in sodium dodecyl sulfate. The aortic enzyme aggregates to species with molecular weights varying from approximately 60,000 to 1,000,000 daltons upon dialysis out of urea into phosphate-buffered saline. Temperature studies reveal that lysyl oxidase is stable to temperatures as high as 80 degrees C, although the assay optimum is 52 degrees C. Studies in progress suggest the temperature dependency of assay may reflect conformational changes in the elastin substrate.
 ...
PMID:Studies on lysyl oxidase of bovine ligamentum nuchae and bovine aorta. 1 72

Lysyl oxidase of bovine aorta was resolved into four enzymically active species by elution from DEAE-cellulose with a salt gradient in 6m-urea, consistent with purification results obtained with enzyme of other tissues [Stassen (1976) Biochim. Biophys. Acta438, 49-60]. In the present study, each of the four peaks of activity was purified to apparent homogeneity by subsequent chromatography on gel-filtration media in 6m-urea. Each enzyme is eluted as a species with mol.wt. approx. 30000 under these conditions, although lysyl oxidase polymerizes to a series of multimers with molecular weights ranging up to 1000000 in the absence of urea. The apparent subunit molecular weight of each enzyme species determined by electrophoresis in sodium dodecyl sulphate and 8m-urea is approx. 32000-33000. The amino acid compositions of the purified forms of lysyl oxidase are similar to each other, although sufficient differences exist to conclude that each is a unique molecular species. Incorporation of alpha-toluenesulphonyl fluoride into the purification scheme does not alter the resolution of enzyme into four species, suggesting that proteolysis during isolation is not the basis of the heterogeneity. The similar sensitivities of each form of enzyme to chelating agents and to semicarbazide and isoniazid indicate that each requires the participation of a metal ion, presumably Cu(2+), and of a carbonyl compound for enzyme function. The present study describes a method for the purification of multiple species of lysyl oxidase and reveals that significant chemical differences exist between the different enzyme forms.
 ...
PMID:Purification and properties of four species of lysyl oxidase from bovine aorta. 3 86

Lysyl oxidase (protein-lysine 6-oxidase; EC 1.4.3.13) is a copper-containing enzyme that functions extracellularly and catalyses the oxidative deamination of peptidyl lysine. Lysyl oxidase was purified 150-175-fold from urea extracts of rat skin and uteri. Features of the enzyme were similar to those reported previously for lysyl oxidase obtained from rat aorta and bovine ligamenture. However, both approximately 40 and approximately 32 kDa polypeptide chains could be isolated from rat skin with apparent lysyl oxidase activity. Antibodies raised in chickens against the approximately 40 kDa form of lysyl oxidase detected the approximately 32 kDa form in immunoblots. Consequently it is inferred that the approximately 32 kDa form of lysyl oxidase is processed from the approximately 40 kDa form of the enzyme. The antibodies were also used to prepare anti(rat lysyl oxidase) affinity columns to facilitate the separation of lysyl oxidase from other proteins in studies to assess the extent to which lysyl oxidase serves as a reservoir for skin copper. At 16 h after an oral dose of copper, as 67Cu, about 6-8% of the total 67Cu incorporated into rat skin was found in association with lysyl oxidase. The lysyl oxidase concentration in rat skin was 2.5-7.5 nmol/g (determined by e.l.i.s.a.). Changing the copper status of rats by feeding a diet deficient in copper did not appear to influence lysyl oxidase accumulation in skin nor the percentage of incorporation of 67Cu in skin as lysyl oxidase. However, when rats were deprived of copper, the functional activity of lysyl oxidase in skin was one-third to one-half the normal values.
 ...
PMID:Purification, properties and influence of dietary copper on accumulation and functional activity of lysyl oxidase in rat skin. 167 61

Inspiration of CdCl2 results in a focally fibrotic response in rat lungs and markedly increases the activity of lung lysyl oxidase. Western blot analyses of urea-extractable rat lung proteins revealed that the levels of an immunoreactive, 32,000-Da protein were markedly increased in the cadmium-exposed rat lung tissue, consistent with the induction of lysyl oxidase protein. Anion exchange chromatography revealed low levels of multiple peaks of catalytically functional lysyl oxidase in control rat lung extracts, while the profile of cadmium-exposed rat lung extracts displayed markedly elevated levels of multiple peaks of enzyme activity indicating that the charge heterogeneity is expressed in the activated enzyme. The cadmium-induced enzyme was purified as a species of 32 kDa, without resolving individual ionic variants. The catalytic and physical properties of the isolated enzyme were very similar to those of previously well characterized basal enzyme of bovine aorta, including the presence of a pyrroloquinoline quinone-like carbonyl cofactor. The copper and cadmium content of the cadmium-induced enzyme indicated little if any replacement of tightly-bound copper by cadmium in the exposed lung.
 ...
PMID:Induction of lung lysyl oxidase activity and lysyl oxidase protein by exposure of rats to cadmium chloride: properties of the induced enzyme. 167 59

Lysyl oxidase was partially purified from serum by a diethylaminoethyl batch procedure in the presence of 6 mol/L urea and dialyzed against 3 mol/L KSCN. Using this method, we determined serum lysyl oxidase activity in 52 patients with liver disease and in 14 healthy controls, and we examined usefulness of serum lysyl oxidase in assessing liver fibrogenesis. For this purpose, serum lysyl oxidase activity in chronic liver disease was compared with serum levels of prolyl hydroxylase and laminin P1. As compared with controls, serum lysyl oxidase activity increased 1.6-fold in chronic persistent hepatitis, 4.4-fold in chronic active hepatitis and 11.8-fold in cirrhosis, indicating an increase in concert with the development of liver fibrosis. In hepatocellular carcinoma, the serum activity, although significantly increased, was lower than that in cirrhosis. Serum prolyl hydroxylase was significantly increased in chronic active hepatitis, in liver cirrhosis and in hepatocellular carcinoma. Serum laminin P1 was significantly increased in chronic active hepatitis, in cirrhosis and in hepatocellular carcinoma. Serum lysyl oxidase activity did not correlate significantly with serum levels of prolyl hydroxylase and laminin P1 in any subject or in any subgroup. The magnitude of the increase and the abnormal percentage of serum lysyl oxidase activity were larger than those for serum prolyl hydroxylase and laminin P1. These results suggest that serum lysyl oxidase activity is a more sensitive indicator of liver fibrosis than serum prolyl hydroxylase and laminin P1.
 ...
PMID:Serum lysyl oxidase activity in chronic liver disease in comparison with serum levels of prolyl hydroxylase and laminin. 168 40

A method is described for the purification of piglet skin lysyl oxidase from a crude urea extract by two simple chromatographic procedures. The method relies on the selective interaction between Sephacryl S-200 and lysyl oxidase that occurs in the absence of urea and in conditions of low ionic strength.
 ...
PMID:Purification of lysyl oxidase from piglet skin by selective interaction with Sephacryl S-200. 197 Feb 38

A modification of the original microdistillation assay for lysyl oxidase is described in which Amicon C-10 microconcentrators are used to separate, by ultrafiltration, the 3H-labeled products released from a [4,5-3H]-lysine-labeled elastin substrate. Enzyme activity is determined by scintillation counting of the ultrafiltrate, after subtraction of radioactivity released in the presence of beta-aminopropionitrile, a specific inhibitor of the enzyme. Conditions are described which optimize both the sensitivity and the efficient use of substrate. The assay shows linear inhibition of activity in up to 1 M urea; hence, as the enzyme is normally diluted in the assay, samples in 6 M urea can be assayed directly, without prior dialysis, and corrected for partial inhibition. Comparable results are obtained when enzyme activity is assayed by ultrafiltration or microdistillation. The assay is simple and convenient and, by using disposable containers throughout, it eliminates the need for time-consuming decontamination of radioactive glassware.
 ...
PMID:An ultrafiltration assay for lysyl oxidase. 197 Nov 60

The spectral and catalytic properties of the copper cofactor in highly purified bovine aortic lysyl oxidase have been examined. As isolated, various preparations of purified lysyl oxidase are associated with 5-9 loosely bound copper atoms per molecule of enzyme which are removed by dialysis against EDTA. The enzyme also contains 0.99 +/- 0.10 g atom of tightly bound copper per 32-kDa monomer which is not removed by this treatment. The copper-free apoenzyme, prepared by dialysis of lysyl oxidase against alpha,alpha'-dipyridyl in 6 M urea, catalyzed neither the oxidative turnover of amine substrates nor the anaerobic production of aldehyde at levels stoichiometric with enzyme active site content, thus contrasting with the ping pong metalloenzyme. Moreover, the spectrum of the apoenzyme was not measurably perturbed upon anaerobic incubation with n-butylamine, while difference absorption bands were generated at 250 and 308 nm in the spectrum of the metalloenzyme incubated under the same conditions. A difference absorption band also developed at 300-310 nm upon anaerobic incubation of pyrroloquinoline quinone, the putative carbonyl cofactor of lysyl oxidase, with n-butylamine. Full restoration of catalytic activity occurred upon the reconstitution of the apoenzyme with 1 g atom of copper/32-kDa monomer, whereas identical treatment of the apoenzyme with divalent salts of zinc, cobalt, iron, mercury, magnesium, or cadmium failed to restore catalytic activity. The EPR spectrum of copper in lysyl oxidase is typical of the tetragonally distorted, octahedrally coordinated Cu(II) sites observed in other amine oxidases and indicates coordination by at least three nitrogen ligands. The single copper atom in the lysyl oxidase monomer is thus essential at least for the catalytic and possibly for the structural integrity of this protein.
 ...
PMID:Structural and catalytic properties of copper in lysyl oxidase. 197 46

Lysyl oxidase activity was assayed in urea extracts of a number of human tissues, proving to be highest in skin. Antibodies to human placental lysyl oxidase completely inhibited the activity of crude lysyl oxidase from all the human tissues studied, with no significant differences in the amounts of antiserum required for 50% inhibition. By contrast, marked differences were found in this value between skin tissue samples from different species. The Mr of lysyl oxidase in crude extracts of human skin and in the medium of cultured human skin fibroblasts was 30 000 by gel filtration, no active species with a higher Mr being detectable. Four forms of lysyl oxidase activity were seen in DEAE-cellulose chromatography of urea extract from human skin, all having Mr 30 000. Antibodies to human placental lysyl oxidase stained a 30 000-Mr protein in urea extracts of all the human tissues studied and in the medium of cultured human skin fibroblasts when examined by immunoblotting after sodium dodecyl sulphate/polyacrylamide-slab-gel electrophoresis, but they also stained high-Mr material. The findings suggest that there are no immunologically distinct lysyl oxidase isoenzymes in the various human tissues and that the true Mr of lysyl oxidase in crude urea extracts is 30 000.
 ...
PMID:Partial characterization of lysyl oxidase from several human tissues. 286 51


1 2 Next >>