Hello, everyone.
I was not able to find a suitable dilution and storage method for the elastase substrate N-succinyl-Ala-Ala-Ala-p-nitroanilide (also known as Suc-Ala). I am planning to dilute it in Tris-HCl buffer, which is the one used for the enzymatic assay proposed by Sigma Aldrich. I will aliquot in small Eppendorf tubes and store it frozen at -80 ºC. Concentration is 2 mg/mL (4 mM).
Tell me if you've done differently.
Thanks!
I would make a stock solution in dimethyl sulfoxide (DMSO) at 10 mM. This can be stored in the freezer. DMSO is miscible with water, and enzymes are fairly tolerant of it, so you can have at least a few percent in the enzyme assay after dilution into assay buffer.
Hello, Adam B Shapiro! Thank you so much for your answer. I did see in a Sigma sheet that this substrate could be dissolved in DMSO, but I was afraid it would interfer in my enzymatic assay, since I am searching for peptides that are possible inhibitors for elastase. Anyways, I ended up doing what I previously said. The first test assays I've run seem to be working fine. I am using the continous spectrophometric rate method from Sigma, available here: https://www.sigmaaldrich.com/technical-documents/protocols/biology/enzymatic-assay-of-elastase.html?gclid=Cj0KCQjwpdqDBhCSARIsAEUJ0hPlvR9xSc0cw-dVkkMRHP8gDVt4cBHh3Y3D8gUKKBUghgh578EolLcaAp4aEALw_wcB. If something goes wrong, I'll post here. Thanks again :)
- Badges
- Science method