Developing an ELISA for Avian Corticosterone Binding Globulin

The chemical response to environmental stressors has been highly conserved throughout evolution and is largely consistent amongst vertebrate animals; this allows avian endocrinologists to use birds as a model for the human stress response. Corticosterone binding globulin (CBG) is a carrier protein for the avian equivalent to cortisol: corticosterone (CORT). Research indicates that CBG's role as a CORT carrier is far more complex than just transport. It is widely accepted that free CORT is the biologically active form, but it is unclear if being bound to CBG (CBG‐CORT complex) inactivates CORT. There is evidence that CBG bound CORT can increase cyclic adenosine monophosphate and evidence that receptors exist for the CBG‐CORT complex in humans. However, it is not known if this is true for birds as well. With so much uncertainty surrounding CBG and its interactions with CORT, it is important to quantify CBG in avian stress studies; including CBG measurements may provide a more complete picture of the avian stress response. CBG is often not quantified in avian CORT research because radioactive assaying is the most common technique for CBG measurement in birds. This project developed an avian CBG enzyme linked immunosorbent assay (ELISA), using a novel CBG antibody developed for the zebra finch ( Taeniopygia guttata), and a recombinant form of zebra finch CBG. This study also examined the reactivity of the CBG antibody against zebra finch on different species of songbirds ( Junco hyemalis , Zonotrichia albicollis , and Zonotrichia leuocophrys) via western blotting, as their CBG sequences vary slightly. Support or Funding Information 2017 ASBMB Undergraduate Research Award to Elizabeth Johnson This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .