A preliminary physico-chemical characterization of a bacterial poly-γ-glutamate sample (96% D-glutamic acid content), γ-D-PGA, in dilute aqueous solutions has been carried out by means of potentiometric, viscosimetric, infrared and chiroptical spectroscopic experiments. The biopolymer exhibits properties strikingly dependent on a number of parameters, mainly: polymer concentration, pH, ionic strength, and nature of added salt. In dilute solutions (polymer concentration around 0.1% w/V) and for pH > 7, γ-D-PGA chains assume elongated, stiff conformations while upon protonation (pH < 3) globular states would prevail. Addition of divalent counterions (Ca(II)) also leads to compact γ-D-PGA conformations.
Aqueous solution properties of bacterial poly-gamma-D-glutamate / Crescenzi, V.; Dalagni, M.; Dentini, Mariella; Mattei, Maria Benedetta. - STAMPA. - 627(1996), pp. 233-242. [10.1021/bk-1996-0627.ch019].
Aqueous solution properties of bacterial poly-gamma-D-glutamate
DENTINI, Mariella;MATTEI, Maria Benedetta
1996
Abstract
A preliminary physico-chemical characterization of a bacterial poly-γ-glutamate sample (96% D-glutamic acid content), γ-D-PGA, in dilute aqueous solutions has been carried out by means of potentiometric, viscosimetric, infrared and chiroptical spectroscopic experiments. The biopolymer exhibits properties strikingly dependent on a number of parameters, mainly: polymer concentration, pH, ionic strength, and nature of added salt. In dilute solutions (polymer concentration around 0.1% w/V) and for pH > 7, γ-D-PGA chains assume elongated, stiff conformations while upon protonation (pH < 3) globular states would prevail. Addition of divalent counterions (Ca(II)) also leads to compact γ-D-PGA conformations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
