Existence of a Novel Hemagglutinin Having No Protease Activity in Vibrio mimicus

The protease elaborated by Vibrio mimicus is known to possess hemagglutinating ability to chicken erythrocytes, the well-known HA/protease. A non-protease hemagglutinin (HA) with strong agglutinating ability towards rabbit erythrocytes was obtained from 32 hr culture supernatant of a pathogenic environmental strain of V. mimicus. This HA (V. mimicus HA: VMHA) appeared stable at relatively higher temperature and agglutinated the erythrocytes from rabbit, guinea pig and mouse but not the erythrocytes from chicken, bovine, horse and sheep. Simple sugars, metal ions and chelating agents failed to inhibit the activity of VMHA. The activity of VMHA was found to be sensitive to digestion by proteolytic enzymes including HA/protease. These results provide evidence for the existence of novel HA other than HA/protease in V. mimicus.     

Fractal property of eye movements in schizophrenia

 On the basis of a temporal model of animal behavior we conducted temporal analysis of eye movements in schizophrenic subjects (n=10) and normal controls (n=10). We found a fractal property in schizophrenic subjects, the fixation time of eye movement during reading ambiguous and difficult sentences showing a clear inverse power law distribution. An exponential distribution of a nonfractal nature was found in normal controls. Received: 21 July 1995/Accepted in revised form: 30 April 1996     

Isolation of a rat mitochondrial release factor. Accommodation of the changed genetic code for termination

A single release factor has been isolated and partially purified from rat mitochondria. It requires ethanol in addition to the specific termination codon when assayed in a heterologous system with Escherichia coli ribosomes. The factor recognizes the codons UAA and UAG but not UGA, and therefore it has been designated mtRF-1. A factor of the bacterial RF-2 type, which in E. coli recognizes UGA, or of the mammalian type, which recognizes all three termination codons, has not been detected in mitochondria. The absence of a factor responding to UGA accommodates the use of this codon as a signal for tryptophan in the rat mitochondrial genetic code. The mtRF-1 could translate all of the known termination codons in the rat mitochondrial genome. It does not respond to AGG and AGA which in bovine and human mitochondrial DNA code for termination but which in rat mitochondria may not code for either an amino acid or for termination.     

Intramolecular crosslinking of gamma-glutamyl transpeptidase

gamma-Glutamyl transpeptidase (rat kidney) is a heterodimeric glycoprotein (subunit molecular weights 52,000 and 25,000). In addition to its single-chain biosynthetic precursor (Mr 78,000), glycosylated high molecular weight forms (Mr 85,000-95,000) have been reported in various rat tissues as well as during in vitro translation of its mRNA. Studies reported here suggest that these might be attributed to the anomalous behavior of intramolecularly crosslinked species. Thus, chemical crosslinking of the purified enzyme (as well as enzyme on the renal brush border membranes) by bifunctional reagents such as dimethyl suberimidate and by an active site-directed reagent, diazotized p-amino-hippurate, produces stable heterodimers which exhibit molecular weights identical to that of the native enzyme when subjected to gel filtration. However, when subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the crosslinked species exhibit apparent Mr values of 85,000 to 110,000, depending upon the crosslinking agent used. Protein glycosylation alone does not account for such anomalous electrophoretic behavior; the extent and the regions of the enzyme involved in formation of crosslinks appear to exert considerable constraints upon their conformation even in denaturing media.     

Rise in age of sexual maturation in male Japanese monkeys at Takasakiyama in relation to nutritional conditions

A few reports have suggested the possibility that feeding conditions might affect the sexual maturation of free-ranging Japanese monkeys in provisionized troops. In the present study, the sexual maturation of male monkeys at Takasakiyama in 1984, nine years after the start of restriction of artificial feeding, was examined externally and histologically and the results were compared with data obtained in 1971, when artificial foods were abundantly given. Spermatogenesis was not observed in any of the males under 4.5 years old in the present study, whereas it was noted in some premature 3.5-year-old males and in all males over 4.5 years old in the 1971 study. The age of sexual maturation thus rose by one or more years over the 13-year period from 1971 to 1984. The lag in sexual maturation of the males at Takasakiyama in 1984 could have been induced by the restriction of artificial feeding.     

Physiological, chemical, morphological, and plant infectivity characteristics of Frankia isolates from Myrica pennsylvanica: correlation to DNA restriction patterns.

The filter exclusion method was used to isolate Frankia strains from Myrica pennsylvanica (bayberry) root nodules collected at diverse sites in New Jersey. A total of 16 isolates from five locations were cultured. The isolates were characterized by morphological, chemical, physiological, and plant infectivity criteria and compared with genomic DNA restriction pattern data, which were used to assign the isolates into gel groups (see accompanying paper). The isolates from M. pennsylvanica evaluated in this study were characteristic of Frankia physiological group B strains and were indistinguishable on the basis of whole-cell wall chemistry and diaminopimelic acid isomer analysis. Distinct differences in the spectrum of utilized organic acids and carbohydrates were observed among the isolates and were the only phenotypic criteria by which the isolates could be separated and assigned into separate groups. In general, isolates within a restriction pattern gel group had identical utilization patterns, whereas intragroup isolates had different utilization patterns. Correlation of these phenotypic characteristics with the results of molecular analysis revealed an exclusive carbohydrate and organic acid utilization pattern for each gel group as established by restriction pattern analysis.     

Structure of cDNA clones for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase from a fern (Asplenium cataractarum rosenstock,aspleniaceae), and its comparison with those of various seed plants

We isolated the small subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO SSu) from a fern,Asplenium cataractarum and determined its 34 N-terminal amino acid sequence. We obtained a cDNA clone that contains the entire coding region of the SSu from the same fern species, using synthetic oligonucleotide probes derived from the above amino acid sequence. It contains a 525 bp open reading frame capable of coding for a polypeptide with 174 amino acids, 31 bp 5′-and 206 bp 3′-noncoding regions. It was also elucidated that the precursor to the SSu contains a transit peptide of 53 amino acid residues and a mature protein of 121 residues. We compared the deduced amino acid sequence of the fern SSu with those of 11 other vascular plant species (including gymnosperms, monocots and dicots). As low as 55% homology was observed between those of a fern and seed plants. Constancy of the amino acid substitution rate in RuBisCO SSu was supported by our relative rate test. Amino acid substitution rate per year per site for RuBisCO SSu was calculated to be 0.81×10⁻⁹ assuming that the separation between pteridophytes and seed plants arose 380 million years ago.