Ultrastructural immunolocalization of lysyl oxidase in vascular connective tissue
نویسندگان
چکیده
The localization of lysyl oxidase was examined in calf and rat aortic connective tissue at the ultrastructural level using polyclonal chicken anti-lysyl oxidase and gold conjugated rabbit anti-chicken immunoglobulin G to identify immunoreactive sites. Electron microscopy of calf aortic specimens revealed discrete gold deposits at the interface between extracellular bundles of amorphous elastin and the microfibrils circumferentially surrounding these bundles. The antibody did not react with microfibrils which were distant from the interface with elastin. There was negligible deposition of gold within the bundles of amorphous elastin and those few deposits seen at these sites appeared to be associated with strands of microfibrils. Lysyl oxidase was similarly localized in newborn rat aorta at the interface between microfibrils and nascent elastin fibers. Gold deposits were not seen in association with extracellular collagen fibers even after collagen-associated proteoglycans had been degraded by chondroitinase ABC. However, the antibody did recognize collagen-bound lysyl oxidase in collagen fibers prepared from purified collagen to which the enzyme had been added in vitro. No reaction product was seen if the anti-lysyl oxidase was preadsorbed with purified lysyl oxidase illustrating the specificity of the antibody probe. The present results are consistent with a model of elastogenesis predicting the radial growth of the elastin fiber by the deposition and crosslinking of tropoelastin units at the fiber-microfibril interface.
منابع مشابه
Role of the extracellular matrix in age-related modifications of the rat aorta. Ultrastructural, morphometric, and enzymatic evaluations.
Connective tissues such as blood vessels are known to be greatly affected by age because of impaired functional properties and increased susceptibility to diseases. With the aim of providing further information on the role of the extracellular matrix in age-related modifications, we investigated the aorta in the rat model from birth to senescence by means of morphological and morphometric obser...
متن کاملThe role of lysyl oxidase-like 1 and fibulin-5 in the development of atherosclerosis and pelvic organ prolapse
The role of lysyl oxidase-like 1 and fibulin-5 in the development of atherosclerosis and pelvic organ prolapse on their study of the correlation between expression of lysyl oxidase-like 1 (LOX-1) and fibulin-5 (F5) in the cardinal ligament tissue and pelvic organ prolapse (POP). In their elegant work, they evaluated the levels of LOX-1 and F5 in connective tissue of the cardinal ligament in ord...
متن کاملDecreased lysyl oxidase activity in the aneurysm-prone, mottled mouse.
Inbred mice bearing certain alleles at the Mottled locus have defects in connective tissue which result in weakness of skin and of blood vessels. Previous studies have established that cross-links in collagen and elastin are decreased in these animals due to impaired formation of lysine-derived aldehydes. Lysyl oxidase activity in extracts of skin is markedly lower in those prepared from affect...
متن کاملCopper, lysyl oxidase, and extracellular matrix protein cross-linking.
Protein-lysine 6-oxidase (lysyl oxidase) is a cuproenzyme that is essential for stabilization of extracellular matrixes, specifically the enzymatic cross-linking of collagen and elastin. A hypothesis is proposed that links dietary copper levels to dynamic and proportional changes in lysyl oxidase activity in connective tissue. Although nutritional copper status does not influence the accumulati...
متن کاملIrreversible Inhibition of Lysyl Oxidase by Homocysteine Thiolactone and Its Selenium and Oxygen Analogues
Homocysteine thiolactone, selenohomocysteine lactone, and homoserine lactone were found to be competitive, irreversible inhibitors of lysyl oxidase, with KI values of 21 6 3 mM, 8.3 6 2.2 mM, and 420 6 56 mM, respectively. The first order rate constants for inactivation (k2) of the enzyme varied over a much smaller range, ranging from 0.12 to 0.18 to 0.28 min for the Se-, thio-, and O-lactones,...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of Cell Biology
دوره 103 شماره
صفحات -
تاریخ انتشار 1986