Iodination of surface components of the spheroidal and ameboid spermatozoa of Ascaris suum (Nematoda)

Purification and characterization of a glycoprotein from the surface of Ascaridia galli

Employing papain as the enzyme and agarose bound Ricinus communis agglutinin as the affinity gel, a glycoprotein has been isolated and purified from the surface of Ascaridia galli. The glycoprotein shows an apparent molecular weight of 68 kilo daltons and contains fucose, galactose, rhamnose and glucosamine as sugar moieties. Only 2% of its entire molecule has been found to possess alpha-helical configuration.

Amino acid and lipid composition of refringent granules from the ameboid sperm of Ascaris suum (Nematoda)

Transformation of the spermatozoon of Ascaris suum from a spheroidal to an ameboid cell is associated with the formation of a motile pseudopodium and coalescence of the intracellular refringent granules. The pseudopodia of the ameboid spermatozoa contain filaments organized into dense patches, bundles, web-like or lace-like networks, as observed by electron microscopy. The morphology and chemistry of the refringent granules were investigated in subcellular fractions enriched for these structures. Isolated refringent granules were heterogeneous in size measuring from 0.5 X 0.6 to 2.3 X 3.5 microns. Each granule is surrounded by a 110 A thick layer. During fusion, the surfaces of the refringent granules form small extensions resembling micropodia. The process of fusion occurs at many sites on a given granule and simultaneous fusion of several granules was commonly observed. Amino acid analyses of the refringent granule proteins (RGP's) indicated: they are rich in aspartic acid or asparagine (48%), leucine (10%), serine (19%) and aromatic amino acids (11%). Gas-liquid chromatographic analyses of alditol acetate derivatives of monosaccharides released by mild acid hydrolysis showed the predominant sugars to be glucose (7.3 micrograms/mg protein), galactose (9.2 micrograms/mg) and N-acetylglucosamine (5.5 micrograms/mg). Lipid analyses indicated a complex mixture of glycerides, ascarosides and waxes, together with a major component that resembled free fatty acid in mobility on TLC.

Subcellular fractions and the refringent granules of the spermatozoa of Ascaris suum (Nematoda)

Six subcellular fractions were isolated by differential centrifugation of the homogenate of spermatozoa of Ascaris suum. The cellular constituents of pelleted fractions, as identified by electron microscopy, were membranes and membranous organelles (fraction A1), microsomal (A2), cytoplasmic (A3), large refringent granules (B1), small refringent granules (B2) and a detergent-soluble fraction (B3). Polypeptide analysis of SDS-PAGE showed that the 18,400-dalton band, one of the major spermatozoan proteins, is detectable in all of the fractions. However, the cytoplasmic (A1) and refringent-granule (B1) fractions contained the highest level. The isolated refringent granules consisted of 2-6% lipid while the nonlipid fraction formed an insoluble matrix with a fibrillar network morphology. This fibrillar matrix contained three polypeptides of small molecular weight (7,000-14,000) in addition to the 18,400-dalton polypeptide. These small polypeptides (7,000--14,000 MW) are detectable only in fractions of the refringent granules and are therefore called the refringent-granule proteins (RGP). These RGP are sensitive to tryptic hydrolysis and have solubility properties similar to the protein, ascaridine.