34] Biosynthesis of insoluble elastin in cell ang organ cultures

Abstract

Publisher Summary The formation of insoluble elastin in in vitro systems such as cell and organ cultures has been the focus of several laboratories in recent years. There are three criteria that can be used in assessing the presence of elastin in cell cultures. These include (a) evaluation of the culture by ultrastructural analyses; (b) evaluation of the insoluble elastin formed by amino acid composition of the product obtained after purification of the elastin; and (c) detection and possible quantification of the formation of the unique lysine-derived cross-links. It is suggested that the cell cultures to be studied should be derived, if possible, from a primary culture that has undergone at least two subcultivations. Studies of elastin synthesis in organ culture systems have therefore been limited to the use of radioactive precursors, such as valine or lysine. Lysine incorporation experiments focus on the formation of cross-links in much the same manner described in the cell culture section. Radiolabeled valine is also commonly used in elastin studies because this protein has an unusually high content of valine. To perform rapid organ culture experiments on insoluble elastin accumulation one can simply employ methods that are quite similar to the preparation of lysyl oxidase or prolyl hydroxylase substrates from aortic explants.