ISSN:
0091-7419
Keywords:
lymphocyte activating factor (LAF)
;
Interleukin I
;
purification of human IL-1
;
hollow fiber diafiltration
;
isoelectric focusing
;
polyacrylamide gel
;
electrophoresis
;
human monocytes
;
endotoxin stimulation
;
IL-1 release
;
thymocyte mitogenic activity
;
Life Sciences
;
Molecular Cell Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Interleukin I (IL-1) is a lymphocyte stimulant released by human monocytes cultured for 18-24 hours in tissue culture medium containing 5% serum and the non-specific immunostimulant lipopolysaccharide (LPS). Human IL-1 is found in the conditioned medium in a low molecular weight (∼ 13,000) and a high molecular weight (∼ 85,000) form. The high MW activity may result from the formation of a complex between IL-1 and serum constituents. During the course of purification, the low MW IL-1 activity is often recovered in a high MW form. Hollow fiber diafiltration and membrane ultrafiltration has been found to rapidly separate low MW IL-1 from all measurable protein with a yield of 4% of the original activity. The IL-1 which converts to the high MW form during the purification is recoverable, 21% of the original activity, but contains small amounts of serum proteins. Isoelectric focusing (IEF) of the low MW IL-1 resulted in a very highly purified sample which was analyzed by polyacrylamide gel electrophoresis (PAGE). Utilizing a new staining procedure which detects less than 1 ng of protein per band, the IEF-purified IL-1 revealed trace quantities ( 〈 1 ng) of a slowly migrating protein similar to immunoglobulin and no other bands. There were no bands which corresponded with the known electrophoretic mobility of IL-1. Since the samples applied to the gel contained significant biological activity, this result implies that human IL-1 is biologically active in picogram quantities.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jss.400130405
