Complete glycan structure of the S-layer glycoprotein of Aneurinibacillus thermoaerophilus GS4-97

Isolate GS4-97 was purified from an extraction juice sample of an Austrian beet sugar factory and affiliated to the newly described species Aneuriniba cillus thermoaerophilus, It is closely related to the type strain of this s pecies, A. thermoaerophilus L420-91(T), and possesses a square surface laye r (S-layer) array composed of identical glycoprotein monomers as its outerm ost cell envelope component. By sodium dodecyl sulfate-polyacrylamide gel e lectrophoresis, the purified S-layer showed an apparent molecular mass of s imilar to 109,000, After thorough proteolytic degradation of this material by pronase E and purification of the reaction mixture by gel permeation, ch romatofocusing, and reversed-phase chromatography, a homogeneous glycopepti de fraction was obtained which was subjected to one- and two-dimensional nu clear magnetic resonance spectroscopy, The combined chemical and spectrosco pic evidence, together with N-terminal sequencing, suggest the following st ructure of the O-glycosidically linked S-layer glycan chain of the glycopep tide: [GRAPHICS] This is the first description of a beta-D-GalNAc-Thr linkage in glycoprotei ns.