endocytosis kinetics - (Sep/21/2009 )

Hello!

I've a question about the mathematical elaboration of kinetic data to establish if a phenomenon of membrane transport can be due to endocytosis. Plotting the initial velocity values against the concentrations of substrate, I obtained a hyperbolic curve, typically associated to a saturable transport. Plotting the velocity values against the log I obtained a sigmoid curve. Can this curve be associated to an endocytosis process? Have you any suggestions to opportunely elaborate these data?

Thank you in advance for your replies.

hyperbolic curves look sigmoidal when you plot them on semi-log. i don't think you can make any decisions based on that phenomenon.

Thanks for your reply!

I was suspecting it wasn't the right way to show endocytosis. In your opinion can I try another mathematic tool to give an indication for an endocytosis phenomenon? Apart from my studies, does it exist? I hope you can help me!

Thanks!!!

i'm not sure that i can help you further. my experience is with enzyme kinetics.

with enzyme kinetics you may use an inverse (lineweaver-burk) plot (1/v vs 1/s). this will give you such information as Vmax and Km.

a hill plot (v/(vmax-v) vs s) plotted on semi-log can help you visualize cooperativity.

Hi!
I've already used Hill and Eadie-Hofstee plots to gain info about the involvement of one or more transporters and cooperativity.

I think it's time to surrender! For weeks I've been searching for a literature reference solving my question !

Thank you so much anyway!!!