title: Isolation and physiochemical properties of protein-rich nematode mitochondrial ribosomes.
abstract: In the present study, mitochondrial ribosomes of the nematode Ascaris suum were isolated and their physiochemical properties were compared to ribosomes of Escherichia coli. The sedimentation coefficient and buoyant density of A. suum mitochondrial ribosomes were determined. The sedimentation coefficient of the intact monosome was about 55 S. The buoyant density of formaldehyde-fixed ribosomes in cesium chloride was 1.40 g/cm(3), which suggests that the nematode mitoribosomes have a much higher protein composition than other mitoribosomes. The diffusion coefficients obtained from dynamic light scattering measurements were (1.48 +/- 0.04) x 10(-)(7) cm(2) s(-)(1) for 55 S mitoribosomes and (1.74 +/- 0.04) x 10(-)(7) cm(2) s(-)(1) for the 70 S E. coli monosome. The diameter of mitoribosomes was measured by dynamic light-scattering analysis and electron microscopy. Though the nematode mitoribosome has a larger size than the bacterial ribosome, it does not differ significantly in size from mammalian mitoribosomes.
authors.affiliation: Department of Integrated Biosciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.forename: Takashi
authors.initials: T
authors.lastname: Ohtsuki
authors.forename: Koji
authors.initials: K
authors.lastname: Yamada
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yoshinari
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kita
authors.forename: Yoh-Ichi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Kimitsuna
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D017165:Ascaris suum / Q000737:chemistry* / Q000166:cytology*; D002499:Centrifugation, Density Gradient; D004926:Escherichia coli / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000737:chemistry* / Q000648:ultrastructure; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism / Q000648:ultrastructure; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D013057:Spectrum Analysis
chemical_list: D012269:Ribosomal Proteins