I heard you have to run a lot of it to really get something out of it. Plus isn't content to the flu ?
yup ive got like 6 mgs , and there are two types ive got the untagged one fs344/315 , not the tagged one fs317/288 which give the flu like symptoms but hey will know only when i start using it lol hopefully its legit
First, understand that I am talking about what is normally called Follistatin 344 (FS344). FS344 is a particular isoform (version) that is different from FS288. Specifically, FS344 does not bind activin well (which you do not want), but still binds myostatin (which you do want). I would not suggest anyone take FS288, because although it may have the same myostatin inhibition, it could have side effects not present with FS344.
Second, FS344 turns into FS315. The FS344 protein undergoes post-translational modification that removes a 29 amino-acid signal sequence from the amino terminal end (the “front”), turning a 344 amino acid protein into a 315 amino acid protein.
Refs:
FST (follistatin)
Molecular heterogeneity of follistatin, an activ... [J Biol Chem. 1993] - PubMed - NCBI
INHIBITION OF MYOSTATIN WITH EMPHASIS ON FOLLISTATIN AS A THERAPY FOR MUSCLE DISEASE
Note that the signal peptide is cleaved off in the golgi, which is inside the cell that produced the FS in the first place. The point of that is that FS344 is actually, with “normal” FS (that is, FS produced by your body), never found in the blood stream. This is because the signal peptide was cleaved off before secretion, and so FS315 is what ends up in the blood.
I previously mentioned that the FS344->FS315 change occurs by chopping a piece off the amino-terminal (also called N-terminal) end. This is important because the N-terminal end is where myostatin binds. (See The structure of myostatin:follistatin 288: insights into receptor utilization and heparin binding : Abstract : The EMBO Journal
Conversely, the other end of the molecule, the carboxy-terminal (also called C-terminal) end, is what, in some forms, binds activin and related cell-surface molecules.
What does that tell us? Making a very broad, and perhaps inaccurate, generalization, if you screw up the N-terminal end of Follistatin, you may disrupt its myostatin binding (bad). If you screw up the C-terminal end of Follistatin, you may disrupt its activin binding (not bad – in fact, we don’t care about that at all, and it’s what we want with the FS344/315 isoform anyway.
So, FS344 and FS315 are related as FS344 generates FS315 (IN CELLS – more on that later). FS288 is not. FS288 has a precursor protein called FS317, instead of FS344. Don’t think that because FS315 and FS317 sound similar that they are. You do not want FS317 or FS288. You want FS344/FS315. And, IMHO, preferably FS315 (but good luck finding that for a reasonable price – it seems like most companies are selling FS344).
sp,e omfo regarding follistatin posted by mc member
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would update all if its any good or bunk