Bio135_assignment_1

Bio135_assignment_1 - Name: Soo-Khee Chia ID #: 005811923...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Name: Soo-Khee Chia ID #: 005811923 Biol 135 Assignment #1 CALCULATION: (8-22) The purification of a protein usually requires multiple steps and often involves several types of column chromatography. A key component of any purification is an assay for the desired protein. The assay can be a band on a gel, a structure in the electron microscope, the ability to bind to another molecule, or an enzymatic activity. The purification of an enzyme is particularly instructive because the assay allows one to quantify the extent of purification at each step. Consider the purification of the enzyme shown in Table 8-1. The total volume, total protein, and total enzyme activity are shown at each step. Procedure Total Volume (mL) Total Protein (mg) Total Activity (units) Specific Activity (units/mg) Crude Extract 2,000 15,000 150,000 10 Ammonium Sulfate Precipitate 320 4,000 140,000 35 Ion-exchange Chromatography 100 550 125,000 227.27 Gel-filtration Chromatography 85 120 105,000 875 Affinity Chromatography 8 5 75,000 15,000 A.For each step in the purification procedure, calculate the specific activity of the enzyme (units of activity per mg of protein). How can you tell that purification has occurred at each step? 150,000 (units of activity) Crude Extract = --------------------------------- =10 (units/mg) 15,000 (mg of proteins) 140,000 (units of activity) Ammonium sulfate precipitation = --------------------------------- =35 (units/mg) 4,000 (mg of proteins) 125,000 (units of activity) Ion-exchange chromatography = --------------------------------- =227.3 (units/mg) 550 (mg of proteins) 105,000 (units of activity)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Gel-filtration chromatography = --------------------------------- =875 (units/mg) 120 (mg of proteins) 75,000 (units of activity) Affinity chromatography = --------------------------------- =15,000 (units/mg) 5 (mg of proteins) If there is an increase in each of the specific activity calculated, we can tell that the purification
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

Bio135_assignment_1 - Name: Soo-Khee Chia ID #: 005811923...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online