Monoclonal antibodies raised against membrane glycoproteins from mouse brain recognize N-linked oligomannosidic glycans

Abstract

Monoclonal L3 and L4 antibodies have been shown to recognize carbohydrate epitopes on several neural cell adhesion molecules; these epitopes can be released by treatment with endoglycosidase H. In the present study, we have identified the oligosaccharides released by endoglycosidase H from the cell adhesion molecules AMOG and LI by fast-atom bombardment mass spectrometry as being solely of the oligomannosidic type. Using neoglycolipids of oligomannosidk glycans, we also report that both antibodies show the highest reactivity with the a-manno-pentaose Manal-3-[Manal-6(Manal-3)Manal-6]-Man, but decreasing reactivity with the a-manno-hexaose, heptaose, octaose and nonaose glycans. Thus, to our knowledge, we describe here for the first time monoclonal antibodies recognizing A L glycosidical]y linked oligomannosidic glycans.

Interactome Analyses Identify Ties of PrPC and Its Mammalian Paralogs to Oligomannosidic N-Glycans and Endoplasmic Reticulum-Derived Chaperones

“…Not only do both proteins harbor Ig-like domains, but a subset of these domains bear a striking resemblance in their sequence, an observation made previously [24],[25]. Interestingly, these very same Ig-like domains are capable of binding to membrane proteins carrying oligomannosidic N-glycans [26],[27],[28],[29]. The latter modification is only found on a relatively small number of mature N-glycosylated proteins expressed mainly in the brain, because oligomannose structures typically represent transient intermediates subject to additional posttranslational modification during their passage through the secretory pathway [26],[29],[30].…”

“…Interestingly, these very same Ig-like domains are capable of binding to membrane proteins carrying oligomannosidic N-glycans [26],[27],[28],[29]. The latter modification is only found on a relatively small number of mature N-glycosylated proteins expressed mainly in the brain, because oligomannose structures typically represent transient intermediates subject to additional posttranslational modification during their passage through the secretory pathway [26],[29],[30]. Amongst the few known proteins carrying oligomannosidic N-glycan structures are the cell adhesion molecule L1, the β-subunit of the Na/K ATPase, the transferrin receptor, integrins [31] and members of the ectonucleotide pyrophosphatase/phosphodiesterase protein family [30].…”

Prion Protein Regulates Glutamate-Dependent Lactate Transport of Astrocytes

“…Antibodies and reagents. Rat monoclonal antibody A2D2 against mouse basigin (Heller et al, 2003), rat oligomannose-reactive monoclonal antibodies L3 and L4 (Schmitz et al, 1993), and rat monoclonal antibody 426 against adhesion molecule on glia (AMOG) (Antonicek et al, 1987) (mouse ␤2-ATPase subunit) were described previously. Polyclonal antibodies against basigin (also called EMMPRIN) (T-18), PrP (M-20), ␣2 Na ϩ /K ϩ -ATPase (C-16), and GluR2 (N-19) were purchased from Santa Cruz Biotechnology (Santa Cruz, CA).…”

“…We therefore determined uptake of lactate in the presence of this monoclonal antibody. In addition, we tested antibodies against oligomannosidic glycans (Schmitz et al, 1993), a synthetic peptide that comprises the carbohydrate binding site within basigin (Heller et al, 2003) and purified oligomannosidic glycans. Interestingly, in all cases, uptake of lactate was increased ϳ1.5-fold (Fig.…”

Prominent 85‐kDa Oligomannosidic Glycoproteins of Rat Brain Are Signal Regulatory Proteins and Include the SHP Substrate‐1 for Tyrosine Phosphatases

“…Oligomannosidic glycans are transient on many glycoproteins early in the biosynthetic pathway and in most cases are subsequently remodeled to hybrid or complex oligosaccharides. However, experiments with antibodies that are specific for oligomannosidic moieties (Schmitz et al, 1993) have shown that glycoproteins expressing this type of glycan reach the cell surface. One example is the adhesion molecule on glia, which corresponds to the β2 subunit of Na + ,K + ‐ATPase, in which 80% of the carbohydrate is oligomannosidic and may mediate cis interactions that modulate the activity of this ion pump (Magyar et al, 1994).…”