The complex-type oligosaccharide binding lectin Datura stramonium agglutinin detects type II A muscle fibres in the branchial biceps from man and cat.

Complex-type oligosaccharides were detected in the sarcoplasm of muscle fibres from cat and human biceps using lectins and anticarbohydrate antibodies. The lectin Datura stramonium agglutinin strongly stained type II A fibres as identified by myosin ATPase activity after alkaline and acid preincubation. In contrast, all muscle fibres showed a moderate coarse granular staining after incubation with Tetracarpidum conophorum agglutinin and Telfairia occidentalis agglutinin which recognize tri-antennary complex glycans poorly bound by D. stramonium agglutinin. Strong sarcoplasmic staining in all muscle fibres was obtained after incubation with an antibody against branched N-acetyllactosamine structure while an antibody against binary 2 --> 3 sialyllactosamine glycans failed to detect the muscle fibres. Treatment of the muscle sections with sialidase prior to incubation with D. stramonium agglutinin did not influence the lectin staining pattern. Staining of blots from electrophoretically separated muscle proteins obtained by homogenization, solubilization and centrifugation of small muscle pieces showed D. stramonium agglutinin binding to a number of bands ranging from 200 kDa to 30 kDa. No D. stramonium agglutinin positive bands were observed in blots from separated mitochondrial proteins while blots from sarcoplasmic reticulum separated by electrophoresis stained many bands in the range from 200 kDa to 30 kDa. It may be concluded that all muscle fibres in human and cat biceps hold intracellular non-sialylated complex-type oligosaccharides and further, that a specific tri-antennary complex-type glycoform is strongly expressed in type II A fibres as recognized by D. stramonium agglutinin. These results indicate a different glycosylation of certain myofibrillar-associated proteins in muscle fibre types.