Poly-y-methyl-L-glutamate

Amino acid polymers like poly(y-methyl-L-glutamate) [29967-97-3] h.a.ve been developed as raw materials for artificial leathers (see Leatherlike materials). Derivatives of amino acids are now finding new appHcations in industry and agriculture. 

Fig. 12 (a) Chemical structure of poly(sarcosine)-b-poly(y-methyl L-glutamate) copolymer. 

Kugo et al. [152] studied the behavior of human fibroblast attachment to RGDS- and GRGDS-peptide-immobilized poly(y-methyl L-glutamate) (PMLG) film via three types of spacer group. 

The synthetic polypeptides poly-L-alanine (—NH. CH(CH3). CO—)p (a form) and poly-y-methyl-L-glutamate... 

Values of piezoelectric constants are, however, very scattered among polymers. In the case of oriented poly(y-methyl L-glutamate) film, the piezoelectric strain constant (d-constant) amounts to as much as 10 x 10 8 cgsesu when elongated in a direction at 45° to the draw-axis (Fukada, 1970), which is comparable with d = 6.5 x 10 8 cgsesu for X-cut... 

Even for poly(y-methyl L-glutamate) with a high piezoelectric constant (d= 10 7 cgsesu), the electro-mechanical coupling constant k defined by... 

Figure 9 shows the result by Fukada, Date, and Hirai (1966) for uniaxially drawn poly(y-methyl L-glutamate) film (PMLG). The conformation of the chains is predominantly the a-helix. The sample was drawn twice as the original length and the frequency of stress was 20 Hz. The observed anisotropy is well expressed by the tensor (59) which leads to the d-constant of the film for elongational stress in the film plane (yz-plane),... 

Fig. 9. Piezoelectric strain constant of uniaxially drawn poly(y-methyl L-glutamate) film (a-helical form) plotted against the angle 6 between draw-axis and stress direction. Draw-ratio = 2. Drawn after Fukada, Date, and Hirai [Nature 211, 1079 (1966)] by permission of Macmillan (Journals) Ltd.

Date,M., Takashita, S., Fukada,E. Temperature variation of piezoelectric moduli in oriented poly(y-methyl L-glutamate). J. Polymer Sci. A-2, 8, 61 (1970). 

Date,M., Hirai.N. Piezoelectric effect in poly-y-methyl L-glutamate. Nature 211,1079 (1966). 

To avoid any complications caused by the intermolecular association, Goodman (78) reinvestigated the optical rotation of the peptides in dimethyl formamide, since in this medium the specific rotation is independent of concentration. From the latter study it was concluded that at 25° C the spontaneous helix formation of poly-y-methyl-L-glutamate in dimethyl formamide is occurring at the critical range of 7—9 units. Extension of these studies (73 b, 79) led to a better understanding of temperature and solvent effects upon the helix-coil transition of oligomeric polypeptides. 

A) The absorbance spectrum of poly-y-methyl-L-glutamate in the a-helical form, with an assignment of its three constituent transitions. (B) The far-UV CD spectrum of the same compound, deconvoluted on the assumption that the shapes of the absorbance and dichroic bands are directly related (broken lines). The solid line is the observed spectrum and the filled circles the sum of the three bands. In general, the sign of a CD band may be either positive or negative, and its intensity does not necessarily follow that of the absorbance band. (From Holzwarth and Doty, 1965.)... 

Baglioni et al. [72] showed that poly (y - methyl L - glutamate) may form a monolayer in the a helice or (3 sheet conformation according to whether the spreading solvent did or did not contain pyridine. 

T. Ooi, R. A. Scott, G. Vanderkooi, and H. A. Scheraga, / Chem. Phys., 46, 4410 (1967). Conformational Analysis of Macromolecules. IV. Helical Structures of Poly-L-atanine, Poly-L-valine, Poly-B-methyl-L-aspartate, Poly y-methyl-L-glutamate, and Poly-L-tyrosine. 

Fig. 8. Polarization spectra of oriented poly-y-methyl-L-glutamate film. The baseline due to prism and quartz support versus gauze has been subtracted. (Grat-zer et al., 1961.)...

The diffraction pattern of poly(L-methionine), Figure 4a, is much more crystalline than that of the other two polymers and in several respects resembles that of collapsed monolayers of poly(y-methyl-L-glutamate). The correspondence is shown clearly by the reciprocal lattice diagrams (Figure 5). For an extended account of the basic theory see Stokes (23) and Elliott (24). 

The close correspondence in size between the hexagonal unit cells of poly(y-methyl-L-glutamate) and poly(L-methionine) implies a similarity in the intensity expected in the observed strong reflections. In particular those on the flfth layer line associated with the pitch of the helix (or on the corresponding layer Une of a higher order helix) indexed as 105 and 115 are normally very strong (18, 24) in poly(y-methyl-L-glutamate). But the 105 reflection is much weaker than the 115 reflection... 

Polymer films have been obtained by plasma polymerization of hexafluorobenzene, N-vinylpyrrolidine, and chloracrylonitrile (Munro). Higuchi et al. have shown that irradiation of an azobenzene-modified poly(Y-methyl-L-glutamate-CO-L-glutamic acid) in bilayer membrane vesicles of distearyldimethylammonium chloride leads to trans-cis isomerization of the polymer this leads to transfer of the polypeptide from the hydrophobic bilayer membrane interior to the hydrophilic surface. As a result, there was a decrease in the ion permeability through the bilayer membrane and the formation of intervesicular adhesion. Eisner and Ritter have prepared photosensitive membranes from an aromatic polyamide and a cinnamate that incorporates a liquid crystalline component. 

Hirayama, C. Sakata, M. Ihara, H. Ohkuma, K. Iwatsuki, M. Effect of the pore size of an animated poly(y-methyl L-glutamate) adsorbent on selective removal of endotoxin. Anal. Sci. 1992, 8, 805-810. 

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