Neuronal subsets express multiple high-molecular-weight cell-surface glycoconjugates defined by monoclonal antibodies Cat-301 and VC1.1.
Cat-301 and VC1.1 are monoclonal antibodies that recognize surface-associated molecules on subsets of mammalian CNS neurons. Earlier work demonstrated that Cat-301 recognizes a 680-kDa chondroitin sulfate proteoglycan (PG). VC1.1 has been shown to recognize 3 polypeptide bands on Western blot analysis; a major band at 95-105 kDa and additional bands at 145 kDa and 170 kDa. In the present report, we show that VC1.1 also reacts with a high-molecular-weight glycoconjugate. Immunoprecipitation experiments and biochemical characterizations indicate that Cat-301 and VC1.1 define at least 3 distinct high-molecular-weight antigens. The VC1.1 antigens react with antikeratan sulfate antibodies, while the Cat-301 antigens do not. By immunodepletion, we show that some VC1.1 antigens are Cat-301 positive, while others are Cat-301 negative. In addition, Cat-301-reactive proteoglycans are heterogeneous with respect to the presence or absence of VC1.1 epitopes. Double-label immunofluorescence studies with these 2 antibodies are consistent with the biochemical results and show that there are 3 classes of immunoreactive neurons in the cat CNS:Cat-301+/VC1.1+, Cat-301-/VC1.1+, and Cat-301+/VC1.1-. These results indicate that structural microheterogeneity exists among Cat-301 and VC1.1 high-molecular-weight glycoconjugates. This heterogeneity may be a reflection of the diverse neuronal phenotypes that are recognized by Cat-301 and VC1.1 in the mammalian CNS.
Department of Neuroanatomy, Yale University School of Medicine, New Haven, Connecticut 06510.
S
S
Zaremba
J R
JR
Naegele
C J
CJ
Barnstable
S
S
Hockfield
D000818:Animals; D000911:Antibodies, Monoclonal; D000941:Antigens / Q000032:analysis; D015153:Blotting, Western; D001921:Brain / Q000166:cytology*; D002415:Cats; D002462:Cell Membrane / Q000032:analysis*; D002531:Cerebellum / Q000166:cytology; D005455:Fluorescent Antibody Technique; D005829:Geniculate Bodies / Q000166:cytology; D006001:Glycoconjugates / Q000032:analysis* / Q000276:immunology; D007163:Immunosorbent Techniques; D007632:Keratan Sulfate / Q000032:analysis / Q000276:immunology; D008970:Molecular Weight; D009474:Neurons / Q000032:analysis*; D011509:Proteoglycans / Q000032:analysis / Q000276:immunology; D012160:Retina / Q000166:cytology; D013116:Spinal Cord / Q000166:cytology*
D000911:Antibodies, Monoclonal; D000941:Antigens; D006001:Glycoconjugates; D011509:Proteoglycans; D007632:Keratan Sulfate