Papain-resistant (f) and papain-sensitive (g) subclasses of rabbit slgA. Allotypic specificities on different domains of the g subclass of α-chains (αg)
✍ Scribed by T. R. Malek; W. Carey Hanly; Katherine L. Knight
- Book ID
- 102822352
- Publisher
- John Wiley and Sons
- Year
- 1974
- Tongue
- English
- Weight
- 654 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0014-2980
No coin nor oath required. For personal study only.
✦ Synopsis
at the Medical Center Chicago Papain-resistant (f) and papain-sensitive (9) subclasses of rabbit slgA
Allotypic specificities on different domains of the g subclass of a-chains (ag)"
Secretory IgA (sIgA) from rabbits homozygous for the f7 1 and g75 allotypic specificities of the f and g subclasses, respectively, was digested into four fractions: sIgA, F c , ~, Fab,, and Fab,. The subclass and allotypic characteristics of each fraction were determined by quantitative radioprecipitation analyses. The f7 1 allotypic specificities were found predominantly in the undigested sIgA (with some in the Faba fragment) and the g75 allotypic specificities were in the FcZa and Fab,, fractions. Previous data from our laboratory indicated that the f72 and f73 sIgA allotypes of the f subclass are resistant t o cleavage and that the g74 sIgA allotype of the g subclass is cleaved by papain. The present and previously reported data support the hypothesis that resistance or sensitivity of rabbit sIgA t o papain digestion is a function of the subclass rather than the individual allotypic specificities.
Quantitative radioprecipitation analyses of the Fc,, and Fabza fragments showed that the "g" allotypic specificities are composed of multiple determinants, some of which reside on the Fd part of the a-chain and some of which reside on the F c part of the a-chain. Anti-allotype antisera have been prepared which are specific for the allotype determinant(s) present on each of the fragments. Of special interest is the ability to serologically distinguish the CH 1 domain on the Fd fragment of a rabbit a-chain.
* The f72g74 sIgA is sIgA obtained from a rabbit homozygous at theflocus p/p2) and at the g locus (g74/g74); f73g74 sIgA IS obtained from a rabbit homozygous at the flocus (f3/p3) and at the g locus (g74/g74); f72f73g74 slgA is obtained from a rabbit heterozygous at the flocus u 7 2 / f 7 3 ) and homozygous at the g locus (g74/g74); f71g7.5 sIgA is obtained from a rabbit homozygous at the flocus v 1 / f 7 1 ) and at the g locus (g75/g75).