Green turtles (Chelonia mydas) have novel asymmetrical antibodies

Journal of Immunology
By: , and 



Igs in vertebrates comprise equally sized H and L chains, with exceptions such as H chain–only Abs in camels or natural Ag receptors in sharks. In Reptilia, Igs are known as IgYs. Using immunoassays with isotype-specific mAbs, in this study we show that green turtles (Chelonia mydas) have a 5.7S 120-kDa IgY comprising two equally sized H/L chains with truncated Fc and a 7S 200-kDa IgY comprised of two differently sized H chains bound to L chains and apparently often noncovalently associated with an antigenically related 90-kDa moiety. Both the 200- and 90-kDa 7S molecules are made in response to specific Ag, although the 90-kDa molecule appears more prominent after chronic Ag stimulation. Despite no molecular evidence of a hinge, electron microscopy reveals marked flexibility of Fab arms of 7S and 5.7S IgY. Both IgY can be captured with protein G or melon gel, but less so with protein A. Thus, turtle IgY share some characteristics with mammalian IgG. However, the asymmetrical structure of some turtle Ig and the discovery of an Ig class indicative of chronic antigenic stimulation represent striking advances in our understanding of immunology.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Green turtles (Chelonia mydas) have novel asymmetrical antibodies
Series title Journal of Immunology
DOI 10.4049/jimmunol.1501332
Volume 195
Issue 11
Year Published 2015
Language English
Publisher The American Association of Immunologists
Contributing office(s) National Wildlife Health Center
Description 9 p.
First page 5452
Last page 5460
Online Only (Y/N) N
Additional Online Files (Y/N) N