Iodine binding capacity and iodine binding energy of glycogen

Abstract

The iodine binding capacity (IBC) of glycogen is around 0.30% (w/w) at 3°C. The amount of iodine complexed comprises about 12.5% of the mass of glycogen that takes part in the glycogen–iodine (GI) complex formation. This suggests involvement of four iodine atoms for every 25 anhydroglucose units (AGU, C6H10O5). Since the chromophore is due to the I4 unit within the helix of 11 AGUs, only 44% of the AGUs (11 out of 25) are involved in the complex formation. The heat of formation of the GI complex is around −40 kJ/mol of I2 bonded. These results suggest remarkable similarities with those of the amylopectin–iodine (API) complex. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1409–1412, 1997

Comparison and Evaluation of the Effectiveness of Two Approaches of Diffusible Iodine‐Based Contrast‐Enhanced Computed Tomography (diceCT) for Avian Cephalic Material

“…; Metscher, ,b; Jeffery et al., ; Holliday et al., ; Gignac and Kley, ; Gignac et al., ). These results suggest a high iodine sorption capacity (I‐I, I 3 − , I 5 − ) in the major component of muscles, the myocytes or glycogen, and lipids (Palumbo and Zullo, ; Lecker et al., ; Li et al., ). Except for the eye lens, stained muscular tissues have the highest grayscale values (Fig.…”

“…Glycogen is one of the major common absorbents of iodine that potentially raises the radiographic contrast during staining (Lecker et al., ; Jeffery et al., ; Li et al., ). We hypothesized that the proportion of glycogen content in a given tissue is a key factor in determining its maximal grayscale values (absorption).…”

Micro-computed tomography with iodine staining resolves the arrangement of muscle fibres

“…One explanation for the retention of iodine in the muscle fibres compared with the connective tissues is that the compound becomes entrapped within the complex structure of glycogen found in muscle cells (Gage, 1906(Gage, , 1917Saenger, 1984;Yu et al, 1996;Lecker et al, 1997). The enhanced contrast on the microCT images would therefore correspond to a relative increase of X-ray absorption in these cells, due to the presence of iodine.…”

Application of micro-computed tomography to microstructure studies of the medicinal fungus Hericium coralloides

“…One explanation for the retention of iodine in certain hyphae might be that the contrast agent becomes entrapped within the complex structure of polysaccharides (e.g. cell wall chitins and glucans), which also was suggested in Yu et al (1996), Lecker et al (1997) and Jeffery et al (2011). The enhanced contrast on the micro-CT images therefore would correspond to a relative increase of X-ray absorption in these cells, due to the presence of iodine, suggesting that chemically different types of hyphae exist.…”