Studies on cystic fibrosis using isoelectric focusing. IV. Distinction between ciliary dyskinesia activity in cystic fibrosis and asthmatic sera and association of cystic fibrosis protein with the activity in cystic fibrosis serum.

The cystic fibrosis protein (CFP) and ciliary dyskinesia activities (CDA) in sera 
from CF homozygotes, heterozygote carriers, and individuals with bronchial asthma have 
been partially purified. Concurrently, the CDA's in sera from patients with 
cystic fibrosis (CF) or bronchial asthma were shown to be different 
substances by ion- exchange or gel permeation chromatographic procedures. Sephadex G-200 
chromatography indicated that the CF-CDA eluted with a protein fraction of 
molecular weight (MW) 68,000-150,000 and that the asthma CDA was found 
in a protein fraction of MV greater than 150,000. The two 
activities could also be separated by DEAE-cellulose chromatography. Prior acidification of 
whole normal, CF homozygote, obligate heterozygote, or asthmatic sera to pH 
3.7 using EDTA, followed by fractionation of Sephadex G-200 removed all 
the CDA's from fractions of highermolecular weight and shifted the activities 
to a protein fraction of MW 1,100-13,700. This procedure afforded a 
200-fold purification of the CDA's in sera from patients with asthma 
or CF. EDTA treatment, however, also generated a CDA in previously 
nonreactive normal sera. Subsequent fractionation of the various active G-200 fractions 
on Bio-Gel P10 allowed for the separation of three separate activities 
(Bio-Gel Fractions I, II-IV, and V). Fraction I was shown to 
represent the activity in sera from patients with asthma and was 
determined to be C3a (MW 9,000). Fraction I was also found 
in normal, CF, and carrier sera and therefore is not a 
specific CDA. Fraction II-IV is thought to represent a CF-specific CDA 
(MW 5,000) since it could not be demonstrated in either normal 
or asthmatic sera but was found in sera of obligate heterozygotes. 
Fraction III-IV also did not react with antisera to human C3a. 
Fraction V was generated from all serum types upon acidification of 
the serum with EDTA and is thought to be a nonspecific 
CDA. Bio-Gel P10 filtration of Sephadex G-200 fractions provided 823-fold and 
650- fold purification of the asthmatic and CF CDA's, respectively. Concurrent 
analysis of column fractions for CDA's by bioassay and for CFP 
by electrofocusing showed CFP only in fractions that contained the CF-CDA. 
Combined analyses employing acid disc gel electrophoresis, isoelectric focusing, and EDTA 
treatment of active CF-immunoglobulin (Ig) G and Sephadex G-200 column fractions, 
followed by Bio-Gel P10 chromatography, provided evidence that CFP was associated 
with the CF-CDA. It is unknown as yet whether CFP itself 
is responsible for the CF-CDA activity. 