Oxidases lysyl

Methoxatin, now known as coenzyme PQQ, was originally obtained from methylotrophic bacteria but is now known to be a mammalian cofactor, for example, for lysyl oxidase and dopamine p-hydroxylase. The first synthesis of this rare compound was accomplished by the route outlined below. In the retrosynthetic analysis both of the heterocyclic rings were disconnected using directly keyed transforms. 

Aminopropionitrile (present in sweet peas) covalently inactivates lysyl oxidase, preventing intramolecular cross-linking of collagen and causing abnormalities in joints, bones, and blood vessels. 

FIGURE 6.21 Collagen fibers are stabilized and strengthened by Lys-Lys cross-links. Aldehyde moieties formed by lysyl oxidase react in a spontaneous nonenzymatic aldol reaction. 

Pyridoxamine phosphate serves as a coenzyme of transaminases, e.g., lysyl oxidase (collagen biosynthesis), serine hydroxymethyl transferase (Cl-metabolism), S-aminolevulinate synthase (porphyrin biosynthesis), glycogen phosphoiylase (mobilization of glycogen), aspartate aminotransferase (transamination), alanine aminotransferase (transamination), kynureninase (biosynthesis of niacin), glutamate decarboxylase (biosynthesis of GABA), tyrosine decarboxylase (biosynthesis of tyramine), serine dehydratase ((3-elimination), cystathionine 3-synthase (metabolism of methionine), and cystathionine y-lyase (y-elimination). 

Fig. 4 Structures and formation routes of crosslinks in elastin. In the first step, lysine is catalyti-cally converted to allysine by lysyl oxidase all subsequent condensation steps are spontaneous...

After secretion from the cell, certain lysyl residues of tropoelastin are oxidatively deaminated to aldehydes by lysyl oxidase, the same enzyme involved in this process in collagen. However, the major cross-links formed in elastin are the desmosines, which result from the condensation of three of these lysine-derived aldehydes with an unmodified lysine to form a tetrafunctional cross-hnk unique to elastin. Once cross-linked in its mature, extracellular form, elastin is highly insoluble and extremely stable and has a very low turnover rate. Elastin exhibits a variety of random coil conformations that permit the protein to stretch and subsequently recoil during the performance of its physiologic functions. 

Associations have also been made between areca and cardiovascular disease, diabetes, and asthma (Winstock et al. in press). Areca may affect cardiovascular disease by increasing homocysteine concentrations and/or through areca copper concentrations and interaction with the lysyl oxidase enzyme (Trivedy et al. 1999). Areca chewing has been associated with cardiac dysrhythmias in a few cases and a case of myocardial infarction was temporally associated with areca use (Hung and Deng 1998 Chiang etal. 1998). 

Figure 12 (a) Lysyl oxidation reaction, (b) cofactor of lysyl oxidase, lysyl tyrosine quinone (LTQ), and (c) an example of the intermolecular cross-link, histidinyl glucosylgalactosyl hydroxylysinorleucine. 

Collagen molecules assemble into fibrils. Cross-linking involves lysyl oxidase, an enzyme that requires and copper. 

For positive controls, it is extremely important to have a tissue culture cell line with an abundant amount of target nucleic acid. Varieties of tissue culture cell lines are available from American Tissue Culture Center, Rockville, MD. Rapidly growing tissue culture cell lines transfected with the target nucleic acid could be successfully used for positive controls. For example, formalin-fixed paraffin-embedded foreskin fibroblast tissue culture cell-line FS4 can be used as a positive control for human lysyl oxidase mRNA detection and c-W-ras transformed RS-485 cell line for normal ras message detection. Thin sections (4-5 im) of paraffin-embedded positive control cell lines could be placed simultaneously near the side of the experimental human or animal tissue. Similarly, one can also use freshly cut animal or human tissue (with the target sequences) preserved, sectioned, and mounted under standard laboratory conditions. For negative controls, choose a cell line (or a tissue) that completely lacks the target nucleic acid see Note 12). 

Copper Liver and organ meats grains, legumes, nuts, seeds (esp. cocoa powder) Component of many enzymes, especially oxidases Amine oxidases Lysyl oxidases Cytochrome oxidase... 

Copper is a component of many enzymes including amine oxidase, lysyl oxidase, ferroxidase, cytochrome oxidase, dopamine P-hydroxylase, superoxide dismutase and tyrosinase. This latter enzyme is present in melanocytes and is important in formation of melanin controlling the colour of skin, hair and eyes. Deficiency of tyrosinase in skin leads to albinism. Cu " ion plays an important role in collagen formation. 

LYSYL OXIDASE METHANE MONOOXYGENASE METHIONINE y-LYASE METHYLAMINE DEHYDROGENASE... 

HORSERADISH PEROXIDASE LACTOPEROXIDASE LIGNAN PEROXIDASE LYSYL OXIDASE MANGANESE PEROXIDASE MYELOPEROXIDASE OVOPEROXIDASE PEROXIDASE PYRUVATE OXIDASE XANTHINE OXIDASE Hydrogen selenide,... 

KINETIC ISOTOPE EFFECT LYSYL ENDOPEPTIDASE LYSYL HYDROXYLASE LYSYL OXIDASE Lysyl residue,... 

The storage role of (Cu,Zn)-SOD in seeds e.g. seems plausible, when the Cu-carrier function of ceruloplasmin is considered The lipophilic anti-inflammatory and anti-ulcer Cu-chelates could also raise the Cu concentration in certain tissues and thus enhance their lysyl oxidase activity. But especially Cu(acetylsalicylate)2 inhibited protine,2-oxoglutarate dioxygenase (EC 1.14.11.2) and lysine,2-oxoglutarate dioxygenase (EC 1.14.1.4), which are also important enzymes in the processing of collagen... 

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