Photomodulation of polypeptide conformation by sunlight in spiropyran-containing poly(L-glutamic acid)

Journal Article · Wed Apr 26 00:00:00 EDT 1989 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00191a076· OSTI ID:7078831

Ciardelli, F ^[1]; Fabbri, D ^[2]; Pieroni, O ^[3]

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1. Univ. of Pisa (Italy) CNR-Center of Stereoordered and Optically Active Macromolecules, Pisa (Italy)
2. Scuola Normale Superiore, ENI, Pisa (Italy)
3. Univ. of Pisa (Italy) CNR-Institute of Biophysics, Pisa (Italy)

Photochromic vinyl polymers, such as polyacrylates containing spiropyran groups, were found to undergo photoinduced variations of their viscosity. Since the viscosity of a polymer system is in part a reflection of polymer conformation, the photoviscosity effects were generically attributed to photoinduced conformational changes of the macromolecules. From the point of view of conformational properties, photochromic polypeptides are much more attractive systems, since they can exist in definite ordered structures such as {alpha}-helix or {beta}-structures, and their conformational variations can be directly investigated by means of CD measurements. In addition, their structure is much more relevant to the proteic nature of biological photoreceptors. In this context the authors report the first preparation of a photoresponsive polypeptide containing spiropyran units in the side chains and clear CD evidence that the polypeptide can undergo large random coil {r equilibrium} {alpha}-helix conformational changes upon exposure to sunlight and dark conditions, alternately. Moreover, irradiation in solvent mixtures having appropriate compositions allows the extent of the photoresponse to be controlled.

• OSTI ID: 7078831
• Journal Information: Journal of the American Chemical Society; (USA), Vol. 111:9; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
POLYPEPTIDES
CHEMICAL PREPARATION
PHOTOCHEMICAL REACTIONS
ABSORPTION SPECTROSCOPY
CONFORMATIONAL CHANGES
EXPERIMENTAL DATA
PHOTOCHROMIC MATERIALS
PHOTOSENSITIVITY
VISIBLE RADIATION
CHEMICAL REACTIONS
DATA
ELECTROMAGNETIC RADIATION
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PEPTIDES
PROTEINS
RADIATIONS
SENSITIVITY
SPECTROSCOPY
SYNTHESIS
140505* - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)