It says in the TBB that the hide glue, sinew glue and other natural glues are made from protein in these parts of the animal, So if you took protein powder and prepared it like a hide glue would it work?

Can't imagine any of the coloring/ flavoring/ preservative agents would be beneficial to bonding strength.  Protein powder is generally derived from either whey (milk) or soy.  Both are readily available, without the undesirable ingredients, at a much lower cost than their by-product dietary supplement powders.  But rather than re-inventing the wheel, why not just buy some rawhide?  Or a dog bone?  Or purchase pre-made hide glue?

I was just wondering. Dont really have nay reason to try it.

knox unflavored geletin can be used as hide glue. don

Glues have certain characteristics that make them perform well as glue.
Different items with the same base can easily have different characteristics.
Feathers and hair are protein based just like hide glue or sinew glue but I'm damned if I can figure out how to make them have the same characteristics as glue.
On the other hand, hide glue makes pretty poor fletching, too.

Guy

Protein powder is largely casein, and casein glue is used in wookworking so I suppose it's possible. Don't know how good it would be though.