Cycloamylose is a mixture of high molecular weight cylcic α-1,4-glucan
produced by the action of 4-α-glucanotransferase on starch
(1). Cycloamylose has a single helica V-amylose conformation,
with an hydrophobic hannel-like cavity (2) and can form an inclusion
complex with various guest molecules.
[Features] Cycloamylose is easily degraded by α-amylases. Upon storage
and handling of cycloamylose, cares should be taken to avoid the
contamination of α-amylases either from human saliva or from
Cycloamylose powder can be stored at room temperature.
Cycloamylose can be dissolved in water to make up to 30 % (w/v)
solution. It is highly recommended to use autoclaved distilled water,
so that to avoid a contamination of α-amylases. The cycloamylose
solution is recommended to store at -20°C.
[NOTE] This reagent cannot be used for protein refolding due to Patent No. 3668091 (Japan) and US6852833 B1.
|<Properties of Cycloamylose>
1. High Solubility in Water
Unlike linea amylose and starch, CA is highly soluble even in cold
water. 0.3 grams or more of CA can be dissolved in 1 mL of hot water.
It is highly recommended to use sterilized distilled water in order
to avoid the dgradation of CA by α-amylases produced by contaminating
microorganisms. The solution of CA does not form precipitate when
stored at 4°C. Upon use and storage of the CA solution, please
avoid the contamination of human saliva or microorganisms, since CA
is easily degraded by α-amylases.
Crystal structures of CA with DP of 26 (CD26) and α-cyclodextrin,
which is cyclic α-1,4-glucan with DP of 6
CD26 in crystal takes a structure in which two anti-parallel
helices of α-1,4-glucan are connected (2) However,
the structure of CD26 in solution is expected to be more flexible
(3) In contrast, α-CD takes a doughnuts-like plane
structure, both in crystal and in solution.
| 2. Inclusion Complex Formation
CA tends to form a helical structure and can incorporate various guest
molecules into its hydrophobic channel-like cavity. Physicochemical
and functional properties of guest molecules, including solubility,
stability, hydrophilic/hydrophobic balance and binding performancees,
are influenced when they form inclusion complexes with CA.
Inclusion complex of CD26 with undecanoic acid
The crystal structure of CD26 complexed with iodine (4), undecanoic
acid and dodecanol (5) had been determined. These guest molecules are
included in the two hydrophobic helical cavities of CD26.
- "The functions of 4-alpha-glucanotransferases and their use for the production of cyclic glucans.", T. Takaha and S. M. Smith, Biotechnol. Genet. Eng. Rev., 16, 257-280 (1999).
- "V-amylose at atomic resolution: X-ray structure of a cycloamylose with 26 glucose residues (cyclomaltohexaicosaose).", K. Gessler, I. Uson, T. Takaha, N. Krauss, S. M. Smith, S. Okada, G. M. Sheldrick, and W. Saenger, Proc. Natl. Acad. Sci. USA, 96, 4246-4251 (1999).
- "Thermus aquaticus ATCC 33923 amylomaltase gene cloning and expression and enzyme characterization: production of cycloamylose", Terada Y., Fujii K., Takaha T. and Okada S., Appl. Environ. Microbiol., 65(3), 910-915 (1999)
- S. Kitamura, et al., Carbohydr. Res., 304, 303-314 (1997)
- "X-ray structure of the cyclomaltohexaicosaose triiodide inclusion complex provides a model for amylose-iodine at atomic resolution", Nimz O., Gessler K., Uson I., Laettig S., Welfle H., Sheldrick GM, Saenger W., Carbohydr. Res., 338(9), 977-986 (2003)
- "Inclusion complexes of V-amylose with undecanoic acid and dodecanol at atomic resolution: X-ray structures with cycloamylose containing 26 D-glucoses (cyclohexaicosaose) as host", Nimz O., Gessler K., Uson I., Sheldrick GM, Saenger W., Carbohydr. Res., 339(8), 1427-1437 (2004)
- S. Kitamura, et al., J. Appl. Glycosci., 50, 321-325 (2003)
- S. Kitamura and Y. Terada, "Fiber Super-biomimetics", NTS, p141.
- C. Urakami, et al., PACIFICHEM 2005
||Wako Catalog No.
[Ezaki Glico Co., Ltd.]