sounds like porcelain berry to me. It pretty much looks and acts like a grape vine, and those berry you described pretty much nails what I see on my own property.

Not sure if its toxic, but its truly a non-issue because you're never gonna be tempted to nibble them again. blech.

They are highly invasive and will smother anything they get near. They also grow super fast.

Tomato Worm,

You have at least 3 species of wild grape in OK; Vitis riparia (riverbank grape), Vitis rotundifolia (muscadine grape) and Vitis cinerea (gray-bark grape). I'm only familar with the riverbank variety, but I can tell you that it's pretty much what you described. The fruit are very bitter/sour, but not poisonous. They are often used to make preserves although I became accustomed to the taste of the unprepared berries as a kid, (kind of like I did with crab apples ;)

I've attached a link to the gray-bark grape as a staring point...

Here is a link that might be useful: Gray-bark Grape

I looked up those species. This vine's fruit is not like that at all. I would have guessed porcelain berry, but these leaves are kelly green and SMOOTH on both sides. Also, not lobed, but serrated. The fruit is dark purple just like a blueberry and has a single, round seed. The pulp is white and runny. The fruits are also green, not white, turn burgundy, then to the dark purple.