Disease relevance of LOX

• Three cell types, including chicken embryonic cells transformed by Rous sarcoma virus, human malignant melanoma cell line LOX, and human breast carcinoma cell line MDA-MB-231, retain the invasive phenotype in vitro, express invadopodia, degrade and enter into a fibronectin-rich collagenous matrix [1].
• Role of elastase and lysyl oxidase activity in spontaneous rupture of internal elastic lamina in rats [2].

High impact information on LOX

• Localization of lysyl oxidase in hen oviduct: implications in egg shell membrane formation and composition [3].
• Lysyl oxidase activity was found in the isthmus (the membrane-forming region) of the hen's oviduct in a copper-rich region proximal to the shell gland [3].
• Desmosine and isodesmosine, cross-linking compounds associated with mature elastin, were found in hydrolysates of the shell membrane, confirming the necessity for lysyl oxidase in its biosynthesis [3].
• Lysyl oxidase inhibitors beta-aminopropionitrile, aminoacetonitrile, semicarbazide, and isonicotinic acid hydrazide were given to newborn chicks, to chick embryos, and to newborn rats, and the ultrastructural alterations of the aortic elastic fibers were analyzed and compared with the extent of the enzyme inhibition [4].
• Data are presented suggesting that matrix glycosaminoglycans (GAGs) prevent spontaneous tropoelastin aggregation in vivo, at least up to the deamination of lysine residues on tropoelastin by matrix lysyl oxidase [4].

Biological context of LOX

• The developmental steady-state levels of lysyl oxidase mRNA together with the mRNAs encoding two of the enzyme's substrates (tropoelastin and type I collagen) increased between 8 and 16 days of embryonic development [5].
• The nucleotide sequence of contiguous chick lysyl oxidase cDNA clones contained an open reading frame of 1260 bases which encodes a predicted protein of 420 amino acid residues (48,150 Da) [5].
• Collagen cross-linking. Purification and substrate specificity of lysyl oxidase [6].
• We propose that the shift in molecular weight is due in part to copper binding and the formation of lysyl tyrosyl quinone, the cofactor at the active site of lysyl oxidase [7].
• We have studied the effect of L-ascorbic acid (vitamin C) on copper metabolism using copper-deficient chicks and the activation of lysyl oxidase copper-dependent enzyme, to assess bioavailability of copper [8].

Anatomical context of LOX

• Lysyl oxidase activity and elastin/glycosaminoglycan interactions in growing chick and rat aortas [4].
• Raising day-old chicks on diets lacking copper severely depressed the activity of lysyl oxidase, a copper metalloenzyme in connective tissue [9].
• Lysyl oxidase was purified 150-175-fold from urea extracts of rat skin and uteri [10].
• Lysyl oxidase, the cross-linking enzyme, was measured in extracts made from the epiphysial cartilages of embryos 24 h after the injection of either 4-deoxypyridoxine or beta-aminopropionitrile [11].
• Lysyl oxidase was extracted from bone and tendon [12].

Associations of LOX with chemical compounds

• Reaction of aortic lysyl oxidase with beta-aminopropionitrile [13].
• Recently, we showed that aldehyde biosynthesis catalyzed by lysyl oxidase occurs after the onset of fibril formation and that nascent aldehydes form Schiff-base cross-links rapidly in fibrils [14].
• In this study, lysyl oxidase from embryonic chick cartilage was purified to constant specific activity and a single protein band on sodium dodecyl sulfate acrylamide gel electrophoresis [6].
• To study this, reconstituted chick bone collagen fibrils were incubated in vitro with highly purified lysyl oxidase and D-penicillamine [14].
• The depletion of pyridoxal phosphate takes approx. 6 h, whereas the inhibition of lysyl oxidase and the increase in collagen solubility occur more slowly [15].

Physical interactions of LOX

• Lysyl oxidase coupled with catalase in egg shell membrane [16].

Other interactions of LOX

• Concentration of collagen, levels of mRNA for collagen type I subunits and for lysyl hydroxylase, and the level of three lysyl oxidase-derived cross-links: dehydro-dihydroxylysinonorleucine (DHLNL), dehydro-hydroxylysinonorleucine (HLNL), and dehydro-histidinohydroxymerodesmosine (HHMD) were determined during 4 wk posthatching [17].
• Moreover, the H(2)O(2) released by lysyl oxidase in ESM was completely decomposed by coexisting catalase activity [16].

Analytical, diagnostic and therapeutic context of LOX

• Administration of CuSO4 either through the diet or through intraperitoneal injections restored the lysyl oxidase activity in aortic tissue [9].
• Molecular cloning and biological activity of a novel lysyl oxidase-related gene expressed in cartilage [18].
• The injection of 5 mg of beta-aminopropionitrile causes the lysyl oxidase activity to fall to 61% of that of saline-injected controls; after treatment with 4-deoxypyridoxine, the activity is 74% of the control value [11].
• The molecular weight of lysyl oxidase was also estimated using matrix-assisted laser desorption ionization/time-of-flight/mass spectrometry (MALDI/TOF/MS) [7].
• An ultrafiltration assay for lysyl oxidase [19].

References