pH Sensitivity of epidermal growth factor receptor complexes

✍ Scribed by Marissa Nunez; Kevin H. Mayo; Cindy Starbuck; Douglas Lauffenburger

• Book ID: 102880257
• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 827 KB
• Volume: 51
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240510310

✦ Synopsis

The association/dissociation binding kinetics of 1251-labeled mouse epidermal growth factor (EGF) to receptors on human fibroblast cells in monolayer culture have been measured at 4°C as a function of extracellular pH from pH 5-9. At pH 8, steady-state total binding is maximal. As pH is lowered to 6.5, total binding monotonically decreases dramatically. It changes further only slightly between pH 6.5 and 5 to about 20% of the maximum binding value. Scatchard binding plots at pH 7.5 and above show the commonly observed concave-upward, non-linear curve; as pH is lowered, this plot becomes much more linear, indicating that the "high affinity" bound receptor population is greatly diminished. Application of our ternary complex binding model [Mayo et al.,