ISSN:
1435-1536
Keywords:
monolayers
;
α-helical form
;
plateau region
;
islets
;
hysteresis cycle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Monolayers of poly-L-methionine (PM) and poly-γ-methyl-L-glutamate (PMG), spread at an air-water interface, exhibit a high compressibility plateau region at 10 dyn/cm and 18 dyn/cm in their respectiveπ-A curves. This behaviour is related to aα-helical conformation of the polypeptide molecules in the said interface. Comparative studies of the areas per residue observed in the spreading isotherms, with the areas calculated from molecular models, indicate that the polypeptide molecules should be associated in parallel, forming islets of at least 5α-helix chains. Mixed monolayers corresponding to the poly-L-methionine (PM)-1,2 dioleyl-L-α-phosphatidylcholine (DOPC) and poly-γ-methyl-L-glutamate (PMG)-1,2 dioleyl-L-α-phosphatidylcholine (DOPC) systems, follow, in every case, the additivity rule for monolayer composition, any indicating that its components are insoluble in the surface mixture. In the case of mixed monolayers of PM-DOPC, a certain degree of compatibility is possible among its components, as a modulation of the plateau region is observed in the spreading isotherms, while for the PMG-DOPC system the plateau region appears at the same surface pressure value as the isotherm corresponding to pure PMG polypeptide.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01451712
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