HEAT-SHOCK TREATMENT RELEASES PENICILLIUM PHOSPHOGLYCOPEPTIDE

Filtrates of heat (54 degrees) treated day-5 Penicillium fellutanum cu ltures contained 70 mg of peptidophosphogalactomannan-II; an unheated control contained 30 mg. The polymer contained up to 60 phosphodiester s, and 5-O-beta-D-galactofuranosyl, mannopyranosyl, amino acyl and 2-a minoethanol residues. Its C-13 NMR Spectrum was nearly identical with that of the control polymer. The major P-31 NMR signal was phosphochol ine phosphodiester at delta 0.22 ppm; significant phosphodiester signa ls occurred at delta 1.15, 1.33 and 1.47. Dilute mineral acid released galactofuranosyl residues from the mannan. Signals at delta 1.15-1.47 ppm were associated with molecules of mass less than 3500 and contain ed galactose, 2-aminoethanol and peptide(s). After this acid treatment , signals at delta 1.0-0.22 remained associated with the mannan. Heat released up to 4-fold more of peptidophosphogalactomannan-III compared with the untreated control; carbohydrate and phosphate content, per m g polymer, were reduced by 4- and 2-fold, respectively. A galactofuran osyl-, phosphoryl- and amino acyl-containing polymer of M-r greater th an 14 000 was solubilized by alkali treatment of P. fellutanum cell wa lls. (C) 1997 Elsevier Science Ltd. All rights reserved.