title: The molecular size and shape of xanthan, xylinan, bronchial mucin, alginate, and amylose as revealed by electron microscopy.
abstract: Electron microscopy of some selected, vacuum-dried and rotary-shadowed, polyelectrolytic polysaccharides and glycoproteins adsorbed to mica indicates that this technique can yield reliable information about polymer conformation for chains with persistence lengths q exceeding about 10 nm. Statistical analyses of the local polymer tangent-direction yield q = 150 nm for double-stranded xanthan, q = 60 nm for single-stranded xanthan, q = 45 nm for xylinan, q = 16 nm for alginate (90% beta-D-mannuronic acid), and q = 15 nm for human-bronchial mucin. These values are all in adequate agreement with values of q obtained by using other techniques. Amylose, on the other hand, appears as non-randomly aligned chains. The observed contour lengths of amylose indicate a mass per unit length of 1440 dalton/nm, consistent with a pseudo-helical conformation.
mesh_terms: D000464:Alginates; D000688:Amylose; D001991:Bronchitis / Q000378:metabolism; D002236:Carbohydrate Conformation; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006801:Humans; D008854:Microscopy, Electron; D008970:Molecular Weight; D009077:Mucins / Q000302:isolation & purification; D011135:Polysaccharides, Bacterial; D013183:Sputum
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D009077:Mucins; D011135:Polysaccharides, Bacterial; C052331:xylinan; D020723:Glucuronic Acid; D000688:Amylose; C002563:xanthan gum