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Updated: Jul 13, 2026
A Convenient and General Expression Platform for the Production of Secreted Proteins from Human Cells
Published on: July 31, 2012
Molecular cloning, overexpression and characterization of human interleukin 1alpha
Dakshinamurthy Rajalingam1, Doreen Kacer, Igor Prudovsky
1Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA.
Insights
Researchers cloned and characterized human Interleukin-1 alpha (IL-1alpha), revealing its folded structure and strong binding to S100A13. This work aids in understanding IL-1alpha release and developing new therapies.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Interleukin-1 alpha (IL-1alpha) is a key regulator of cellular processes.
- Understanding IL-1alpha's structure and interactions is crucial for its biological roles.
Purpose of the Study:
- To clone, express, and characterize human IL-1alpha.
- To investigate its biophysical properties and biological activity.
- To explore its interaction with S100A13.
Main Methods:
- Recombinant protein expression in E. coli.
- Purification using affinity and size exclusion chromatography.
- Characterization via fluorescence, 2D NMR, CD, and ITC.
Main Results:
- High-yield expression and purification of recombinant human IL-1alpha.
- Confirmation of a folded conformation with a beta-barrel structure.
- Demonstration of strong binding to S100A13 and cytostatic effects on endothelial cells.
Conclusions:
- The study provides the first comprehensive characterization of human IL-1alpha.
- Findings facilitate structural studies on IL-1alpha's non-classical release.
- Results offer a basis for designing inhibitors targeting IL-1alpha-mediated diseases.
Abstract:
Interleukin-1 alpha (IL-1alpha) regulates a wide range of important cellular processes. In this study for the first time, we report the cloning, expression, biophysical, and biological characterization of the human interleukin-1alpha. Human IL-1alpha has been expressed in Escherichia coli in high yields ( approximately 4mg per liter of the bacterial culture). The protein was purified to homogeneity ( approximately 98% purity) using affinity chromatography and size exclusion chromatography. Results of the steady-state fluorescence and 2D NMR experiments show that the recombinant IL-1alpha is in a folded conformation. Far-UV circular dichroism (CD) data suggest that IL-1alpha is an all beta-sheet protein with a beta-barrel architecture. Isothermal titration calorimetry (ITC) experiments show that the recombinant IL-1alpha binds strongly (K(d) approximately 5.6 x 10(-7) M) to S100A13, a calcium binding protein that chaperones the in vivo release of IL-1alpha into the extracellular compartment. Recombinant IL-1alpha was observed to exhibit strong cytostatic effect on human umbilical vascular endothelial cells. The findings of the present study not only pave way for an in-depth structural investigation of the molecular mechanism(s) underlying the non-classical release of IL-1alpha but also provide avenues for the rational design of potent inhibitors against IL-1alpha mediated pathogenesis.
