Azobenzene-containing poly(l-glutamates). Photochromism and conformation in solution

Houben, Julien L.; Fissi, Adriano; Bacciola, Domenico; Rosato, Nicola; Pieroni, Osvaldo; Ciardelli, Francesco

doi:10.1016/0141-8130(83)90018-1

Cited by 44 publications

(23 citation statements)

References 26 publications

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“…12 PGA and am.-MG/GA with 3mol% of AN in the side chains were obtained in the same way as AN-PMG. It should be noted that, in the fluorescent modification of am.-MG/GA, an AN group was necessarily introduced to the anionic face of the amphiphilic ex-helix rod.…”

Section: Fluorescent Probesmentioning

confidence: 98%

Interaction between an Anionic Amphiphilic Sequential Polypeptide and Anionic Bilayer Membrane

Higuchi

Kinoshita

Takizawa

et al. 1991

Polym J

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ABSTRACT:The interaction between an anionic amphiphilic sequential polypeptide and an anionic bilayer membrane composed of sodium dilaurylphosphate (DLPNa) was investigated and compared with hydrophobic polypeptide-DLPNa bilayer membrane and anionic polypeptide-DLPNa bilayer membrane interactions. A hydrophobic polypeptide, poly(y-methyl L-glutamate) (PMG, M,=4400), was incorporated into the DLPNa bilayer membrane due to their hydrophobic interaction. The incorporation of PMG, however, did not effectively increase sodium ion permeability across the DLPNa bilayer membrane. There was no appreciable interaction between an anionic polypeptide, poly(L-glutamic acid) (PGA, M,=9200), and anionic DLPNa bilayer membrane because of Coulombic repulsion. On the other hand, an anionic amphiphilic sequential polypeptide, poly(y-methyl L-glutamate-co-L-glutamic acid) (am.-MG/GA), of molecular weight 4300 whose a-helix was anionic on one face consisting of L-glutamic acid and hydrophobic on the opposite face comprising of y-methyl L-glutamate was easily incorporated into the anionic DLPNa membrane and remarkably increased sodium ion permeability based on a transmembrane bundle consisting of amphiphilic helical rods. It was shown, moreover, that lithium ion apparently decreased the sodium ion permeation through the DLPNa bilayer membrane containing where MG and GA denoted 1 1-methyl Lglutamate and L-glutamic acid residue, respectively. A solid condensed monolayer of poly-(y-methyl L-glutamate) (PMG) at an airwater interface was first formed. The PMG side chains hydrated in the aqueous phase were selectively saponified, keeping the remaining side chains oriented away from the aqueous phase unreacted (Figure 1). As a result, the * To whom correspondence should be addressed.

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Section: Fluorescent Probesmentioning

confidence: 98%

Interaction between an Anionic Amphiphilic Sequential Polypeptide and Anionic Bilayer Membrane

Higuchi

Kinoshita

Takizawa

et al. 1991

Polym J

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“…The polymers were obtained by treating high molecular weight poly(l-glutamic acid) with p-aminoazobenzene in the presence of dicyclohexylcarbodiimide (DCCI) and N-hydroxy-benzotriazole (HOBt). [21,22] The photochromic reactions are illustrated in Figure 3. When the modification reaction was carried out in the presence only of 13 DCCI, the modified polymers were found to contain considerable amounts of N-acylureic groups originating from side reactions between DCCI and the c-carboxylic acid functions.…”

Section: Azobenzene-containing Poly(l-glutamic Acid)mentioning

confidence: 99%

Photoswitchable Polypeptides

Ciardelli¹,

Pieroni²

2001

Molecular Switches

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“…8 We describe here the standard procedure employed when the modification reactions were carried out in the presence of trimethylacetyl chloride (pivaloyl chloride, PvC1). -Poly(L-glutamic acid) (Mu = 200,000) (0.450 g; 3.45 mmol COOH groups) was dissolved in a mixture of anhydrous dimethylformamide (DMF) (120 mL) and chloroform (20 mL).…”

Section: Experimental Azobenzene Modification Of Poly(l-glutamic Acid)mentioning

confidence: 99%

Azobenzene‐Containing polypeptides: Photoregulation of conformation in solution

et al. 1984

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SynopsisPhotochromic polypeptides, with 16 to 56% azobenzene groups in the side chains, have been prepared by reaction of poly(L-glutamic acid) with paminoazobenzene, both in the presence of dicyclohexylcarbodiimide/N-hydroxybenzotriizole and of pivaloyl chloride. Analogous modification reactions carried out on polyk-aspartic acid) were unsuccessful owing to the formation of N-succinimide rings. In trimethylphosphate, all the azopolypeptides exhibit the a-helix CD pattern. Irradiation produces the tram-tocis isomerization of the azo side chains, but does not induce any variations of the backbone conformation. In water, the CD spectra indicate the presence of appreciable amounts of a helix in 16 and 21% mol azo-containing poly(bglutamates), while a fi structure is present in a 36% mol azopolypeptide. Light produces conformational changes of the polypeptide conformation which are completely reversed in the dark. The extent and kind of photobehavior depend on the azo content and the pH value at which irradiation is carried out. The light-induced effects are discussed on the basis of the pH-induced order-disorder conformational transitions. In fact, the pK values and the transition curves of the dark-adapted samples were found to be different from those of the irradiated ones.

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Azobenzene-containing poly(l-glutamates). Photochromism and conformation in solution

Cited by 44 publications

References 26 publications

Interaction between an Anionic Amphiphilic Sequential Polypeptide and Anionic Bilayer Membrane

Interaction between an Anionic Amphiphilic Sequential Polypeptide and Anionic Bilayer Membrane

Photoswitchable Polypeptides

Azobenzene‐Containing polypeptides: Photoregulation of conformation in solution

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