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MOLECULAR WEIGHT AND ELECTROPHORESIS OF CRYSTALLINE RIBONUCLEASE
1Laboratories of The Rockefeller Institute for Medical Research.
The Journal of General Physiology
|October 30, 2009
Summary
This study characterized ribonuclease, finding it to be a homogeneous protein with a molecular weight of approximately 12,700. These findings challenge the previously accepted universal unit weight for proteins.
Area of Science:
- Biochemistry
- Protein Chemistry
Background:
- Ribonuclease is an enzyme crucial for RNA degradation.
- Understanding protein molecular weights is fundamental in biochemistry.
Purpose of the Study:
- To determine the purity and molecular characteristics of crystalline ribonuclease.
- To establish the isoelectric point and homogeneity of ribonuclease in solution.
Main Methods:
- Electrophoresis was used to assess purity and determine the isoelectric point.
- Ultracentrifugation was employed to evaluate homogeneity.
- Sedimentation and diffusion measurements were conducted to calculate molecular weight.
Main Results:
- Electrophoresis confirmed the absence of impurities.
- The isoelectric point was determined to be approximately pH 7.8.
- Ultracentrifuge studies showed a single moving component, indicating homogeneity.
- Molecular weight was calculated to be 12,700 using sedimentation and diffusion data, consistent with equilibrium measurements.
Conclusions:
- Purified crystalline ribonuclease is a homogeneous protein.
- The determined molecular weight of ribonuclease (12,700) suggests the universal unit weight of 17,600 for proteins may be inaccurate.
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