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981.
Two different cell wall antigens, carbohydrate (CHO) and protein (P), from Clostridium botulinum type E Saroma were extracted with sodium dodecyl sulfate (SDS) and purified by chromatography on DEAE-Sepharose CL-6B and Sephadex G-75 or G-100. The CHO antigen was composed of glucose, galactose, glucosamine, galactosamine, alanine and phosphorus with a molar ratio of 1.5:1.5:0.25:0.25:1:1. The P antigen was an acidic protein with a molecular weight of 60 kDa, in which the major amino acids were aspartate, glutamate and serine, while the minor ones were cysteine and methionine. Thin sections of the intact or SDS-extracted cells of the organism demonstrated that the cell wall was composed of a two-layered structure, an inner layer about 20 nm thick and an outer layer about 10 nm, and by the extraction with SDS, the outer layer disappeared from the cell surface, leaving the inner layer. Immunogel diffusion tests demonstrated that either CHO antigen or P antigen was common among the nonproteolytic strains of C. botulinum. 相似文献
982.
Takumi Oti Keita Satoh Daisuke Uta Junta Nagafuchi Sayaka Tateishi Ryota Ueda Keiko Takanami Larry J. Young Antony Galione John F. Morris Tatsuya Sakamoto Hirotaka Sakamoto 《Current biology : CB》2021,31(1):103-114.e5
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983.
ABSTRACTThe planorbid species that were described by Shuichi (Syuiti) Mori from Japan have long been enigmatic and their taxonomy has been highly confused. This situation is also an impediment to action for the conservation of Japanese planorbids which are one of the most threatened freshwater snail groups in the country. Based on our examination of Shuichi Mori’s collection stored in the Kyoto University Museum, type materials of the taxa described by him are re-illustrated and re-examined for the first time. Our examination suggested that Gyraulus amplificatus (Mori, 1938) is not a morphological form of Gyraulus biwaensis but a distinct species. Gyraulus pulcher (Mori, 1938) can be regarded as a junior synonym of Gyraulus chinensis. 相似文献
984.
Takumi Takeuchi 《Biologia》2010,65(5):874-879
Dermatopontin is a tyrosine-rich acidic extracellular matrix protein of 22 kD with possible functions in cellmatrix interactions
and matrix assembly. Database of GenBank+EMBL+DDBJ sequences from Nucleotide, Gene, and Expressed Sequence Tag (EST) Divisions
was searched with a keyword “dermatopontin” or mouse dermatopontin amino acid sequence. In addition to five mammals previously
described, five mammalian, two bird, one fish dermatopontin genes were detected in vertebrates. Additionally, a goat EST was
also shown as goat dermatopontin missing 5′-end of the coding region. Moreover, a mRNA sequence of rhesus monkey dermatopontin
was identified, but the deduced amino acid sequence was terminated abruptly due to a nonsense codon. For three 6-residue repeat
regions (D-R-E/Q-W-X-F/Y) that may function as part of a glycosaminoglycan binding site, the first repeat sequence is D-R-Q-W-N-Y
in all mammals while Glutamine is substituted for Leucine in birds. The second and the third repeats are conserved in all
vertebrates. The N-Y-D sequence, the consensus in many amine oxidases, is conserved in mammals except rodents. Asparagine
is substituted for Threonine in birds. The tetrapeptide R-G-A-T sequence possibly recognizing the integrin family is conserved
in mammals and birds, but Alanine was substituted for Glutamine in zebrafish resulting in loss of activity. In conclusion,
functionally significant amino acid sequences in vertebrate dermatopontins are conserved in mammals, while they are not necessarily
identified in birds and fish. The original function of vertebrate dermatopontins may be glycosaminoglycan binding and functions
as a ligand for integrin and an amine oxidase may be gained in the process of evolution. 相似文献
985.
Journal of Plant Research - The article Theoretical models for branch formation in plants 相似文献
986.
987.
Photosynthesis Research - Acaryochloris marina is a unique cyanobacterium that contains chlorophyll (Chl) d as a major pigment. Because Chl d has smaller excitation energy than Chl a used in... 相似文献
988.
989.
Homogeneous fragments of exosporium were isolated and purified from mature spores of a highly sporogenic mutant derived from Clostridium botulinum type A strain 190L. The exosporium was composed of three lamellae and showed a hexagonal array when negatively stained. The hexagonal array of isolated exosporium was resistant to sodium dodecyl sulfate, urea, dithiothreitol, and proteolytic enzymes such as trypsin, pronase, and nagarse, except for pepsin. The hexagonal array was partially disintegrated with 5 M guanidine-HCl and almost completely disrupted with 8 M urea in combination with 1% mercaptoethanol under alkaline conditions. The purified exosporium fraction was composed mainly of protein (69.1%) and lipids (13.8%). A small amount of amino sugars (2.5%) was present, but neutral sugars could not be detected. The exosporium protein had a predominantly acidic amino acid composition accompanied by low levels of cystine, methionine, and histidine. 相似文献
990.
S layer protein of Clostridium tetani strain AO 174, a nontoxigenic derivative of strain Harvard A 47, was prepared from the cell walls by 4 M urea extraction and purified by DEAE-Sepharose CL-6B chromatography followed by a combination of anion-exchange chromatography and reverse-phase chromatography using an HPLC system. The molecular weight of the S layer protein was estimated to be 140 kilodaltons (kDa) by SDS-PAGE. The amino acid composition of the 140 kDa protein was very similar to those of S layer proteins from the other bacterial species: it was rich in acidic amino acid and lacked cysteine. Also, the protein was unique in its extremely low content of proline (0.02 to 0.03 mol%). Multiple isoelectric forms ranging from pH 4.0 to 4.5 were observed in the purified preparation. Immunodiffusion analysis showed that the 140 kDa protein was a common antigen to the three strains of C. tetani tested. 相似文献