Occurrence of the Inv genetic markers in the subgroups of human kappa chains

Congenic mouse strains: the expression of a hidden immunoglobulin allotype in a congenic partner strain of BALB-c mice

This paper derives from the unexpected observations of the "wrong immunoglobulin allotype" in a congenic partner strain of BALB/c mice from the Institute of Cancer Research (ICR CB-17). These mice were specially bred so as not to differ from BALB/c mice in any known way except to carry immunoglobulin structural genes of the C57BL/Ka allotype. In this respect, ICR CB-17 mice were defined as allotypically homozygous according to the Mendelian inheritance of mouse allotype markers. The homozygosity of these mice was challenged, however, when in certain instances immunoglobulins of the BALB/c allotype appeared in the serum of some ICR CB-17 mice. The appearance of this hidden allotype was usually transient and only associated with immunoglobulins of the IgG (IgG2a) class. The implications of these findings for the inheritance and expression of immunoglobulin structural genes are discussed.

Glycopeptides from human kappa-chains

Glycopeptides have been isolated from tryptic digests of kappa-type light chains separated from human myeloma proteins obtained from the serum of two patients, Car and Rai. The glycopeptides are derived from the variable region of the chain in both cases, but from different sections. On the basis of homology it is deduced that glycopeptide from Car, kappaI type, is derived from position 25-31 whereas that from Rai, kappaII type, is from position 62-77, their sequences being respectively Ala-Ser-Gln-Asn-Ile-Ser and Phe-Ser-Gly-Ser-Gly-Ser-Gly(Thr,Asp)Phe-Thr-Leu-Asx-Ile-Ser-Arg. The significance of the results is discussed in connexion with the nature of the attachment site of carbohydrate to protein.