Xenon as an Everyday Indispensable Ligand

A couple of times, and that is plenty, I've had pointless discussions with people who themselves thought they were having victorious arguments, on the subject of substances so dilute their postulated biological effects had to exist. Precisely because such (unnamed) substances were impossible to measure, I was supposed to accept that they were capable of anything. No, I don't accept any such thing: you have to demonstrate it, and until you do, I don't care. Fortunately, one interlocutor was a longtime friend and the other a spare-time door-to-door political canvasser, and in both cases both of us were late for supper, so acrimony was minimal. And the idea's half-formedness is forgivable. It isn't wrong from the get-go; it just needs a lot of work. Below nutrients, micronutrients, and ultramicronutrients, is there yet another category of a-molecule-here-and-there nutrients?

Xenon isn't a nutrient, but under certain circumstances it has at least one biological effect (anesthesia) and it is known to bind to various proteins in measurable amounts at predictable points. It does what it is currently known to do only when delivered at concentrations well above its natural occurrence in air. But it is everywhere, every living thing must have a little inside it, getting all of it out of a living thing in order to test the consequences of its absence cannot be an easy experiment, and some xenon must be lodged on some biomolecules at any given time in any given lifetime. Might these very occasional and/or fleeting visitations be biologically significant?

Imagine the "biological significance" is that xenon's job is not to help something salubrious do its bit, but rather to keep something noxious off, or out. Xenon might be good for this: its concentration is steady and reliably low, no one's ever going to run out of it, and this kind of job suits a material that is after all inert. One might picture an enzyme which catalyzes the production of a baneful material, but it has to oligomerize before it can catalyze anything and just one Xe, anywhere in the complex, causes it to fall apart. Or a foul substance might travel through a transmembrane pore in which there are numerous binding sites for Xe: just one Xe, anywhere in the lumen, blocks the pore.

I decided I had to give up these ideas, however, as who could ever believe one atom could make a 1000-mer thermodynamically untenable, or a pore could have hundreds of binding sites on its inner surface. Instead, I came up with the following: a noxious and highly labile substance is produced and released into a cell membrane, through which it creeps laterally. It's much more stable if it complexes (whatever that means) with certain molecules in the membrane. Thus its survival and its progress depend on meeting another such molecule just after vacating the last one, AND (all this is such a stretch, I admit) when it meets the next one, it DOESN'T have a xenon atom sitting fat and happy in its seat. It can decompose while waiting for that Xe to hive off according to its own binding constant. If it does, then xenon has done its job.

Sooooo, try setting all the following variables:

And on the assumptions that we're looking at the progress and fortunes of, say, 1000 toxin molecules, over and over at this ill-defined interval, with expiry of a given toxin molecule when its cumulative chance-of-survival drops below 1%, what happens?