Protein concentration standards 0.6 0.5 0.4 0.3 0.2 0.1 0.5 1 1.5 2.5 Albumin concentration (mg/mL) A standard curve of known concentrations of protein were reacted with the Biuret reagent. A linear curve fit is presented above. Use the graph to estimate the concentration of an unknown sample with an Ass0 value of 0.416 (A rough estimate is fine. You do not need a calculator for this problem) • Use the graph to estimate the concentration of an unknown sample with an A550 value of 0.233 • Which instrument did we use to measure the intensity of the color of proteins that reacted with Biuret reagent? OSSV

Materials - 2021FA-CHM-1O X Bb 4427577 d-fleet02-xythos.content.blackboardcdn.com/6086c260d7e8f/4427577?X-Blackboard-Expiration=1633143600000&X-Blackboard-Sig 6 / 9 100% Exercise 1: Standard Curve for Protein Measurements: A standard curve for protein concentration is often created using known concentrations of bovine serum albumin (protein). This process is called the Bradford Assay; it is a colorimetric assay. A special reagent turns blue when it binds to amino acids present in protein. The intensity of the color is best measured with a spectrophotometer (a device for comparing two light radiations, wavelength by wavelength). In the case of the Bradford Assay the greater the absorbance, the higher the protein concentration. A series of tests were performed on some samples and spectrophotometer: following measurements were obtained using a Protein Concentration (mg/ml) Absorbance (A) 0.26 0.098 0.56 0.213 0.383 0.84 1.12 0.473 1.40 0.527 TASKS: 1. Enter the data into Excel - the…

You are given a pure protein sample to characterize and provided the following information: Its molar extinction coefficient, ε280, is 0.25 liters micromole-1 cm-1 in both the folded and unfolded form            Its ΔGo for unfolding is 1.5 kcal/mol at 37o  (where RT = 0.59 kcal/mole) A) Using a 0.5 cm pathlength cell, you measure the absorbance at 280 nm of a 20-fold dilution of your pure protein in solution (by this, we mean that 50 ul of the protein sample was diluted to a final volume of 1 ml) and find A280 = 0.40. What is the original concentration of the protein before dilution? B) What is the concentration of the unfolded form of the protein in your sample?

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