Effect of 6059-S,a novel oxacephem,on cross-linking reaction of peptidoglycan biosynthesis in Escherichia coli,Pseudomonas aeruginosa and Serratia marcescens

The effect of 6059-S, a novel 1-oxacephem, on peptidoglycan synthesis was investigated using ether-treated cells of Escherichia coli K 12, Pseudomonas aeruginosa KM 338 and Serratia marcescens IFO 12648. The cross-linking reaction of peptidoglycan synthesis in these organisms was inhibited by markedly low concentration of 6059-S.Non-standard abbreviations PBP penicillin binding protein - MIC minimum inhibitory concentration - ETB ether treated bacterial cells - SDS sodium dodecylsulfate     

Effect of indole-3-acetic acid on cell wall loosening: Changes in mechanical properties and noncellulosic glucose content of Avena coleoptile cell wall

The effect of indole-3-acetic acid on cell wall loosening andchemical modifications of noncellulosic components of the cellwall in Avena coleoptile segments was studied and the followingresults were obtained. (1) Auxin decreased both the minimum stress-relaxation time(T_o) and the noncellulosic glucose content of the cell wall. (2) Decreases were observed in the absence or presence of mannitolsolution at concentrations lower than 0.20 M which osmoticallysuppressed auxin-induced extension, while at concentrationshigher than 0.25 M, there was little auxin effect, indicatingthat it is turgor-dependent. (3) The decrease in T_o of the cell wall and that in the noncellulosicglucose content caused by auxin in the presence of mannitolsolutions of various concentrations paralleled each other (thecorrelation coefficient was 0.897). (4) Both decreases in T_o and glucose content caused by auxinwere inhibited by nojirimycin (5-amino-5-deoxy-D-glucopyranose)in the presence of mannitol. The results suggest that auxin-induced cell wall loosening iscaused by the degradation of noncellulosic rß-glucanin the cell wall. (Received December 24, 1976; )     

Supercoiled DNA folded by nonhistone proteins in cultured mouse carcinoma cells.

Upon gentle lysis of exponentially growing mouse carcinoma cells FM3A by sodium dodecyl sulfate, DNA was released as a "DNA-protein complex" in a folded conformation. No histones could be detected in the DNA-protein complex. The proteins bound to DNA were found to be composed of several kinds of nonhistone proteins with a molecular weight range of 50,000 to 60,000; they appear to play a key role in stabilizing and maintaining the compact and folded structure of the complex. Removal of the proteins by Pronase or 2-mercaptoethanol produced a more relaxed structure sedimenting about half as fast as the original complex in a neutral sucrose gradient. DNA in the folded complex is supercoiled, as indicated by the characteristic biphasic response of its sedimentation rate to increasing concentration of various intercalating agents, actinomycin D, ethidium bromide and acriflavine, with which the cells were treated before lysis. Pronase- or 2-mercaptoethanol-treated relaxed DNA still possessed the characteristic of closed-circular structure as judged from its response to intercalating agents. Nicking with gamma-ray or 4NQO broke these superhelical turns and relaxed the folded complex to slower sedimenting forms equivalent to the relaxed DNA obtained on treatment with Pronase or 2-mercaptoethanol. Viscometric observations of DNA-protein complex were consistent with the above results. A tentative model for the structure of this DNA-protein complex is proposed in which supercoiled DNA is folded into loops by several kinds of nonhistone proteins. Autoradiographic examination of the complex appeared to support this model.     

Auxin-indnced changes in barley coleoptile cell wall composition

Auxin induces extension growth of barley coleoptile segments,causing cell extension and cell wall loosening represented bya change in mechanical properties of the cell wall. This responsedecreased after the segments were starved for more than 12 hrin buffer solution. Auxin decreased the noncellulosic glucosecontent of the cell wall of the segments starved for 0 and 6hr, but very little that of segments starved for 12 and 18 hr.The contents of arabinose, xylose and galactose, among noncellulosicpolysaccharides, and -cellulose of the cell wall increased duringthe starvation, but auxin did not affect them. The auxin-induceddecrease in glucose content was inhibited by nojirimycin, apotent inhibitor of ß-glucanase, which inhibited auxin-inducedextension and changes in mechanical properties of the cell wall,suggesting that cell wall loosening, and thus cell extension,resulted from partial degradation of ß-glucan of thecell wall. (Received April 20, 1978; )     

Identification of two novel GTP-binding protein alpha-subunits that lack apparent ADP-ribosylation sites for pertussis toxin

Molecular cloning of cDNAs encoding alpha-subunits of guanine nucleotide-binding regulatory proteins (G-proteins) has revealed the existence of nine species of alpha-subunits. We have identified two additional G-protein alpha-subunits, which we refer to as GL1 alpha and GL2 alpha, by isolating bovine liver cDNA clones that cross-hybridized at reduced stringency with bovine Gi1 alpha-subunit cDNA. The deduced amino acid sequences of GL1 alpha and GL2 alpha share 83% identity with each other and show 45-55% identity with those of other known G-protein alpha-subunits. Both GL1 alpha and GL2 alpha lack a consensus site for ADP-ribosylation by pertussis toxin. Messenger RNA corresponding to GL2 alpha was detected in all tissues examined, but GL1 alpha mRNA was detected only in liver, lung, and kidney. Antiserum prepared against a synthetic pentadecapeptide corresponding to the deduced carboxyl terminus of GL2 alpha specifically reacted with a 40-kDa protein in mouse liver, brain, lung, heart, kidney, and spleen. The amount of the 40-kDa protein was highest in brain and lung. We suggest that GL1 alpha and GL2 alpha are new members of a subfamily of pertussis toxin-insensitive G-proteins.     

Collagen-induced arthritis in mice. Relationship of collagen-specific and total IgE synthesis to disease.

The relationship between production of IgE and collagen-induced arthritis in mice was examined. Collagen-specific IgE was produced as a consequence of immunization of DBA/1 mice with chicken type II collagen emulsified in CFA. We observed a rise in collagen-specific IgE antibody levels at the onset of CIA clinical and histologic signs in DBA/1 mice. This rise in IgE paralleled that of IgG2a anticollagen antibodies, an isotype implicated in the pathogenesis of CIA by other laboratories. The collagen-specific IgE contained in the plasma of mice with CIA could arm basophils for Ag- (collagen) dependent degranulation. Collagen-specific IgE may thus contribute to CIA by promoting mast cell degranulation in the synovia of susceptible mice immunized with chick type II collagen; but, further work is required to establish such a role for IgE in CIA. However, genetic differences in disease susceptibility could not be accounted for by quantitative differences in collagen-specific IgE production. Further, comparable levels of IgE anticollagen antibodies were observed in animals with active CIA and after spontaneous remission, thereby confirming that the presence of such antibodies is insufficient for disease. Total IgE levels peaked just before spontaneous remission indicating active production of IL-4. IL-4 was administered to animals with CIA to determine if this lymphokine could be involved in the remission process. IL-4 facilitated remission of CIA. Enhanced total IgE production may thus be a marker for activation of Th2 cells that produce lymphokines such as IL-4 and IL-10, factors that may be involved in the spontaneous remission process.     

The Pro to glycine mutation of staphylococcal nuclease simplifies the unfolding—folding kinetics

Kinetics of unfolding and refolding of a staphylococcal nuclease mutant, in which Pro¹¹⁷ is replaced by glycine, have been investigated by stopped-flow circular dichroism, and the results are compared with those for the wild-type protein. In contrast to the biphasic unfolding of the wild-type nuclease, the unfolding of the mutant is represented by a single-phase reaction, indicating that the biphasic unfolding for the wild-type protein is caused by cis-trans isomerization about the prolyl peptide bond in the native state. The proline mutation also simplifies the kinetic refolding. Importance of the results in elucidating the folding mechanism is discussed.     

Geographical distribution of Polycelis (Seidlia) auriculata in Japan

Polycelis (Seidlia) auriculata is endemic to mountain districts of Japan, from the central part of Honshû to the area of the Daisetsu Mts of Hokkaidô. In northern Japan, it sometimes occurs in cold-water biotopes of lowland areas. The progenitor of P. auriculata appears to have been the oldest immigrant into northern Japan among the Japanese Polycelis species, entering through a northern route as a preglacial faunal element. P. auriculata now shows a discontinious distribution in northern Japan. By virtue of its geographical and vertical distribution, ecological niche, variation in anatomy of the copulatory apparatus, and cytodemes, this species appears to be in the process of transformation.     

Reproductive parameters of female Japanese macaques: Thirty years data from the arashiyama troops,Japan

Over a 30-year period from 1954 to 1983, 975 live births were recorded for Japanese macaque females at the Iwatayama Monkey Park, Arashiyama, Japan. Excluding unknown birth dates, primiparous mothers gave birth to 185 infants (182 cases with age of mother known) and multiparous mothers gave birth to 723 infants (603 cases with age of mother known). The peak month of birth was May with 52.3% of the total births occurring during the period. Multiparous females who had not given birth the previous year did so earlier than multiparous females who had given birth the previous year and also earlier than primiparous females. Among the females who had given birth the previous year, females whose infant had died gave birth earlier than females who had reared an infant the previous year. The offspring sex ratio (1:0.97) was not significantly different from 1:1, and revealed no consistent association with mother's age. Age-fecundity exhibited a humped curve. The annual birth rate was low at the age of 4 years but increased thereafter, ranging between 46.7% and 69.0%, at between 5 and 19 years of age, but again decreased for females between 20 and 25 years of age. Some old females displayed clear reproductive senescence. The infant mortality within the first year of age was quite low (10.3%) and the neonatal (less than 1 month old) mortality rate accounted for 49.0% of all infant deaths. There was no significant difference between the mortality rates of male and female infants. A female's rank-class had no apparent effect on the annual birth rate, infant mortality, and offspring sex ratio. These long-term data are compared with those from other primate populations.