Gel Filtration of Lignosulphonic Acids and Peptide-Precipitating Abilities of the Separated Fractions

Abstract

Lignosulphonic acids in dialysed sulphite spent liquor and purified lignosulphonic acids were subjected to gel chromatography on Sephadex G-75, G-100 and G-200 and the fractions tested for peptide-precipitating ability. About 56 % of the total lignosulphonic acids in the dialysed sulphite spent liquor had estimated molecular weights above 90000 and about 72 % above 44000. About 94 % of the purified lignosulphonic acids had molecular weights above 90000 and the remaining 6 % had above 36000. The major peptide-precipitating activity of the lignosulphonic acids was due to fractions with molecular weights in excess of 90000. The percentage of peptides in the peptide-lignosulphonic acid precipitates was found to be 80–90. The molecular weights of the peptides used were found to have an upper limit of about 20000. The lower limit for molecular weights of lignosulphonic acid-precipitating peptides is estimated to be below 6000.

Sammendrag

En har separert rensede ligninsulfonsyrer og ligninsulfonsyrer i dialysert sulfittlut på Sephadex gel G-75, G-100 og G-200 og undersøkt peptidpresipiterende evne hos de ulike fraksjoner. Det ble funnet at ca. 56 % av ligninsulfonsyrene i dialysert sulfittlut hadde estimert molekylvekt over 90000 og ca. 72 % over 44000. Ca. 94 % av de rensede ligninsulfonsyrer hadde molekylvekt over 90000 og de resterende 6 % over 36000. Den største peptidpresipiterende evne ble funnet i fraksjoner med molekylvekt over 90000. En fant at innholdet av peptider i peptidligninsulfonsyrepresipitatene var 80–90 %. Peptidene som er brukt hadde molekylvekt under ca. 20000. Den nedre grense i molekylvekt for peptider som danner presipitat med ligninsulfonsyrer ble estimert til å være mindre enn 6000.