6533b838fe1ef96bd12a4f02

RESEARCH PRODUCT

Degradation of Acetylenic Triacylglyceroles and the Inactivation of Membrane Preparations from Moss Protonema Cells

subject

description

Protonema cells of the moss Ceratodon purpureus accumulate triacylglycerols with two acetylenic fatty acids, 9,12-octadecadien-6-ynoic acid (18:2A) and 9,12,15-octadeca-trein-6-ynoic acid (18:3A), as main components. By following the incorporation of the [14C]-precursors acetate, linoleate, α-linolenate, γ-linolenate, stearidonate and 18:2A, into 18:3A in triacylglycerol accumulating cells, the pathway for acetylenic acids could be established. 18:2A and 18:3A could be synthesized by a second desaturation of the Δ6 double bond of γ-linolenate and stearidonate, respectively. However the major pathway for 18:3A synthesis was via a Δ15 desaturation of 18:2A. Since 18:2A was found exclusively in the triacylglycerols of the cell, there is evidence that the triacylglycerols in Ceratodon purpureus can act as a direct substrate for the Δ15 desaturation [1]. Our next goal is to confirm these in-vivo results by demonstrating the pathways in vitro with subcellular fractions of the moss cells. In the following we will report mainly on the obstacles we met on our way to successful in-vitro experiments. Cell fractionations, in-vitro measurements and analyses were carried out according to established methods [1], [3], [4].