Cryoprotectant biosynthesis and the selective accumulation of threitol in the freeze-tolerant Alaskan beetle, Upis ceramboides.

ABSTRACT: Adult Upis ceramboides do not survive freezing in the summer but tolerate freezing to -60 degrees C in midwinter. The accumulation of two cryoprotective polyols, sorbitol and threitol, is integral to the extraordinary cold-hardiness of this beetle. U. ceramboides are the only animals known to accumulate high concentrations of threitol; however, the biosynthetic pathway has not been studied. A series of (13)C-labeled compounds was employed to investigate this biosynthetic pathway using (13)C{(1)H} NMR spectroscopy. In vivo metabolism of (13)C-labeled glucose isotopomers demonstrates that C-3-C-6 of glucose become C-1-C-4 of threitol. This labeling pattern is expected for 4-carbon saccharides arising from the pentose phosphate pathway. In vitro experiments show that threitol is synthesized f

SUBMITTER: Walters KR 

PROVIDER: S-EPMC2719318 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature