Journal of Neuroscience, Vol 10, 2985-2995, Copyright © 1990 by Society for Neuroscience
Neuronal subsets express multiple high-molecular-weight cell-surface glycoconjugates defined by monoclonal antibodies Cat-301 and VC1.1
S Zaremba, JR Naegele, CJ Barnstable and S Hockfield
Department of Neuroanatomy, Yale University School of Medicine, New Haven, Connecticut 06510.
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.