Related Experiment Videos
Purification of an acid-stable bovine leukocyte interferon
1Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602.
Insights
This study details a method for purifying bovine leukocyte interferon (BoL-IFN) using KSCN precipitation and gel chromatography. Optimal purity was achieved without fetal bovine serum (FBS), with ethylene glycol enhancing recovery.
Area of Science:
- Veterinary Immunology
- Biochemistry
- Molecular Biology
Background:
- Bovine leukocyte interferon (BoL-IFN) is crucial for antiviral immunity in cattle.
- Efficient purification methods are needed for BoL-IFN research and therapeutic applications.
Purpose of the Study:
- To develop and optimize a purification protocol for natural BoL-IFN.
- To characterize the purity and molecular weight of the purified BoL-IFN.
Main Methods:
- BoL-IFN was produced from bovine peripheral blood leukocytes induced with Sendai virus.
- Concentration via KSCN precipitation (pH 3.5) and purification using gel column chromatography.
- Elution buffer composition (ethylene glycol) and fetal bovine serum (FBS) effects on recovery and purity were evaluated.
- Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used for molecular weight determination and purity analysis.
Main Results:
- Higher BoL-IFN recovery from precipitation was observed with increased FBS concentration.
- Maximal purity of BoL-IFN was achieved using crude BoL-IFN with no FBS.
- The addition of 25% ethylene glycol to the elution buffer significantly increased IFN activity recovery (>93%) compared to no ethylene glycol (25%).
- SDS-PAGE analysis of purified BoL-IFN (from no FBS crude material) revealed a single band at 19,000 Da, confirming high purity and identity of the activity with the polypeptide.
Conclusions:
- A practical and efficient method for purifying natural BoL-IFN has been established.
- The optimized protocol yields highly pure BoL-IFN suitable for antibody production and further biological studies.
Abstract:
Bovine leukocyte interferon (BoL-IFN), produced in bovine peripheral blood leukocytes after priming and induction with Sendai virus, was concentrated by precipitation with KSCN (pH 3.5) and purified by gel column chromatography. Recovery of BoL-IFN from precipitation was higher when crude BoL-IFN containing more fetal bovine serum (FBS) was used. However, purity of BoL-IFN recovered from the gel filtration column was highest when crude BoL-IFN with no FBS was used. The use of 25% ethylene glycol in the column elution buffer resulted in over 93% recovery of the applied IFN activity, versus only 25% when buffer contained no ethylene glycol. Column-purified BoL-IFN was further concentrated by ultrafiltration and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in denaturing buffer. When crude BoL-IFN containing no FBS was used for purification, BoL-IFN from a selected column fraction applied to SDS-PAGE resulted in a single narrow band with an apparent molecular weight (MW) of 19,000 Da. Extraction of the SDS-PAGE gel resulted in a single peak of IFN activity indicating identity of the activity and the polypeptide. This proved to be a practical method for obtaining sufficient quantities of purified natural BoL-IFN for use in the production of monoclonal antibodies to BoL-IFN and other biological experiments.