|
|
||||||||
The Journal of Immunology, Vol 141, Issue 8 2529-2535, Copyright © 1988 by American Association of Immunologists
ARTICLES |
WY Almawi, PJ Dolphin, RL Thies, WR McMaster, JG Levy and BL Pope
Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada.
The lymphokine suppressor cell-inducing factor (SIF), obtained from 15 liters of serum-free culture supernatants of the natural suppressor cell line, M1-A5, has been purified to apparent homogeneity by a combination of gel filtration, ion exchange chromatography, and reverse- phase-HPLC. Purity of SIF was assessed by the migration of the factor as a single band on SDS-PAGE, and the elution from reverse-phase-HPLC column as a single and sharp peak. SIF activity was retained after both procedures. Two protein factors with SIF activity were isolated from M1- A5 culture supernatants. The first protein factor (SIF alpha) had a Mr of 43 kDa, and the second protein factor (SIF beta) had a Mr of 6 kDa. Final purification of SIF alpha yielded 5 micrograms protein with specific activity of 4 x 10(6) U/mg protein. Final purification of SIF beta yielded 40 micrograms protein with specific activity of 7.5 x 10(7) U/mg protein. The relationship between SIF alpha and SIF beta, as well as the relationship with other suppressor factors, will be addressed.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |