How to calculate concentration of a protein based on known concentration and mw of other protein

I have a Peptide A (mw = 5074Da), the table below showed measured concentration by Qubit from 5uM up to 80uM solution. All under 20uL solution.

Below is the standard plot for Peptide A (not sure if it's relevant or not):

Let's say I have another Peptide B (mw = 3102Da), how can we calculate the expected Qubit read of Peptide B based on Peptide A (just by calculation)?

For example just for 1 node: 20uM.

• It does not seem to me to be linear. May 24, 2022 at 6:17
• I mean there is consistent bending down and that questions justification of linear approximation. May 24, 2022 at 6:34
• What is "nodes"? Please add some clarification on the concentration units, as these are orders of magnitude different (measured vs nominal). If you read the manual you'll see that the measured concentration can vary ~12% between proteins, but this will apply to peptides only if the functional principle of the assay still applies. I would think it's ok. May 24, 2022 at 9:57
• science.smith.edu/cmbs/wp-content/uploads/sites/36/2015/09/… May 24, 2022 at 9:57
• @BuckThorn Thanks so much for your reply. Nodes is the concentration in the peptide solution I put in the tube (before adding the working solution) to be measured with Qubit. May 24, 2022 at 11:45