This project proposes to examine the structures of low and high molecular weight mycelial glycopeptides from Penicillium charlesii and to determine whether these polymers serve as precursors and/or points of attachment or anchors for peptidophosphoglactomannans(pPGMs) or the extracellular glycohydrolases, phosphatases and proteases that are co-released with pPGMs. In order to establish the precursor/product relationships between the mycelial glycopeptides and the extracellular pPGMS, the structures of the cell wall, membrane, and extracellular pPGMs will be characterized. The structural relationships between the glycopeptides will be investigated by one and two dimensional NMR spectroscopy and GC/mass spectrometry in conjunction with amino acid analyses of peptide components. In addition, the biosynthetic relationships will be probed by using radiolabeled carbohydrate and peptide precursors and by biotinylation of cell walls, followed by isolation of the corresponding glycopeptides from the cell wall, membrane, and extracellular fractions. Establishing the anchor of these glycopeptides to the cell wall or membrane is important to the understanding of the physiological events leading to the release of pPGMs, hydrolytic enzymes, and potential allergens from the Penicillium charlesii.
