Dear Ankit

I do not understand your question fully. By sequester, do you mean binding of phosphate to amylase or inhibition of activity? We have been working with pancreatic amylase for at least 20 years and have always used phosphate buffered saline (PBS) for assays. I cannot speak for non-mammalian amylases but PBS does not inhibit our enzyme. It is just possible that a strong phosphate buffer (rather than PBS) could bind essential Ca+ ions and so inhibit but a literature search should allow you to sort this out.

Peter

First, there is a pH range where a particular buffer exacts its effect the most. For Phosphate buffer it is usually between pH 6.0 and 7.4. Above this (pH 8-9), Tris-HCl is most suited and below this range (pH 4.5- 6.0), Acetate buffer is preferable for assays.

Now for microbial amylases, the choice of buffer is very important in the assay procedure as the pH of the assay medium is one of the distinguishing factor between alpha amylase and beta amylase activity assay. The former is mostly assayed for around pH 6.0 - 6.9 using phosphate buffer while the latter is better assayed for at pH 4.5 - 5.5 using Acetate buffer preferrably.