Biosynthesis of glycophosphatidylinositol-anchored membrane glycoproteins proceeds through the attachment of a preformed glycolipid onto a C-terminal amino acid rapidly after translation. Here we describe the structural analysis of two very polar glycolipids which can be observed after metabolic labeling of lymphoma cell lines S1A and EL-4 with either tritiated myo-inositol, mannose, or ethanol...

This study was carried out in the Parque Municipal das Araucárias, located in the municipality of Guarapuava (PR) from May (06) to April (07). Its aim was to investigate which plants are used by Megachile (Moureapis) sp in provisioning of larvae, and to verify if this bee is oligolectic or polilectic. The collection of the plants was carried out during the bees activity period and in an area co...

The major high mannose-type glycopeptides present in Chinese hamster ovary cells have the compositions (Man)9(GlcNAc)2-Asn, (Man)8(GlcNAc)2-Asn, and (Man)6(GlcNAc)2-Asn. The structures of these glycopeptides were determined by the combination of methylation analysis, acetolysis, Smith periodate degradation, and alpha- and beta-mannosidase digestion. Their complete structures are: manalpha1 lead...

A particle-bound enzyme from the fungus imperfectus Cryfitococcus taurentii var. flavescens (NRRL Y-1401) mediates transfer of mannosyl units from GDP-mannose to endogenous primer. The enzyme requires divalent cations for activity. The pH optimum is ‘7.5 and the apparent K, for GDP-mannose is 0.14 mbr. A polysaccharide fraction that is associated with the enzyme was found to be similar to a pol...

Several ninhydrin-positive lipids were found in methanogenic bacteria and the structure of one of them, designated as PNL2 from Methanobrevibacter arboriphilus, was identified as a diphytanyl ether analog of phosphatidylserine. The chromatographic behavior of the lipid on thin-layer plates and on a DEAE-cellulose column was identical to the ester form of phosphatidylserine. The infrared spectra...

Lipid-linked oligosaccharides were synthesized with the particulate enzyme preparation from mung bean (Phaseolus aureus) seedlings in the presence of GDP-[(14)C] mannose. The oligosaccharides were released from the lipids by mild acid hydrolysis and purified by several passages on Biogel P-4 columns. Five different oligosaccharides were purified in this way. Based on their relative elution cons...

The predators Hippodamia convergens Guérin-Menéville (Coleoptera: Coccinelidae) and Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), are frequently observed on vegetable crops, especially on tomato plants, as well as on flowers of several plants around crop fields. It is well known that when predators feed on pollen and nectar they can increase their longevity and reproductive capacity. T...

A comparative ultrastructural study of Araceae pollen walls was conducted for the first time. The results are based mainly on investigations by transmission electron microscopy of 101 species in 70 genera (out of a total of 105 genera), while pollen of 83 genera with 219 species were studied by scanning electron microscopy, generally without acetolysis. Special attention was given to Lemnaceae ...

The structure of the cell-wall mannan from the J-1012 (serotype A) strain of the polymorphic yeast Candida albicans was determined by acetolysis under mild conditions followed by HPLC and sequential NMR experiments. The serotype A mannan contained beta-1,2-linked mannose residues attached to alpha-1,3-linked mannose residues and alpha-1,6-linked branching mannose residues. Using a beta-1,2-mann...