Photoreversible absorption changes of guanidine-HCltreated phycocyanin and allophycocyanin isolated from the blue-green alga Tolypothrix tenuis

In the search for the photoreceptor in photocontrolled phycoerythrinformation, photoreversible absorption changes of chromoproteinsin vivo and in vitro were studied with the blue-green alga Tolypothrixtenuis. Neither intact cells nor crude extracts of soluble proteinsshowed any significant absorption changes which were reversiblyinduced by green and red light. However, the photoresponse wasobservable when the crude protein extracts were treated withthe chaotropic reagent guanidine-HCl (0.4 M, for 1 hr in thedark). Isolated phycocyanin and allophycocyanin also showedthe same photoresponse after the guanidine-HCl treatment. Thedifference spectrum (green minus red) of guanidine-HCl-treatedphycocyanin was almost identical with that shown by phycochromea of Bj?rn and Bj?rn (3), and the allophycocyanin showed thesame difference spectrum as those of phycochrome c of Bj?rnand Bj?rn and the photoreversible pigment isolated by Scheibe(7). Urea at a concentration higher than 1 M or alkaline incubation(pH 8.5) also showed the same effect. The results were interpretedas indicating that phycocyanin and allophycocyanin obtain theability for photoresponsiveness when their protein conformation,probably around the chromophore site, is modified. (Received October 30, 1978; )     

Carotenoid photobleaching induced by photosystem II action in the membrane fragments of the blue-green alga Anabaena variabilis : Action of O2

Carotenoid photobleaching induced by photosystem II action wasstudied using membrane fragments of the blue-green alga Anabaenavariabilis. Special attention was paid to the action of O₂. Carotenoid photobleaching elicited by carbonyl cyanide m-chlorophenylhydrazone(CCCP) depended on O₂. However, the addition of H₂O₂, sodiumsilicotungstate or potassium ferricyanide (Ferri), an electronacceptor for reaction center II action, removed the O₂-dependency.These results indicate that O₂ acts as the electron acceptorfor this reaction. When both CGCP and Ferri were present, a short illumination(0.25 sec) caused a rapid photobleaching followed by a slowrecovery in the subsequent dark period. The spectrum of theabsorption decrease in the light was identical with that ofthe absorption increase in the subsequent dark, indicating thata reversible process is involved in the carotenoid photobleaching.The size in the dark recovery relative to the light bleachingbecame larger under anaerobic conditions and smaller under higherpartial pressure of O₂. The reuslts were interpreted as indicatingthat O₂ does not function in the primary process including areversible bleaching step, but is involved in the slow and irreversiblebleaching process. (Received April 3, 1978; )     

Adsorption of Saccharomyces cerevisiae onto cellulose and ECTEOLA-cellulose films for ethanol production

Epichlorohydrin-triethanolamine (ECTEOLA)-cellulose films (paper and cloth) have been found to bind Saccharomyces cerevisiae cells which were able to develop metabolically active colonies on the surface of the films. Unmodified cellulose films also bound the yeast but to a lesser extent. Film fermenters were constructed by coiling a double layer of the cloth and copper screen and vertically placing the resulting cartridge into a column. These film fermenters were able to convert the sugars (14%) in the hydrolysate of a Jerusalem artichoke tuber into ethanol, with 90% of the theoretical yield after 6 h of fermentation. The bound yeast produced ethanol at a specific rate of 1.0 g ethanol per g cell per hour.     

Differences in the pregnancy-terminating effectiveness of an LH-RH analogue by subcutaneous, vaginal, rectal, and nasal routes in rats

A long-acting analogue of LH-RH, des-Gly10-[D-Leu6]-LH-RH-ethylamide (TAP-144), was administered once or twice on day 9 of pregnancy by subcutaneous, vaginal, rectal, and nasal routes to rats; the pregnancy-terminating effectiveness of these routes was determined on day 14. When rats were given a single dose of TAP-144, the ED50 value was 1.2 micrograms/100 g body weight by the vaginal route, the effectiveness being 752 and 1,221 times higher than those by the subcutaneous and rectal routes, respectively. Nasal administration was not effective in terminating pregnancy even at a high dose of 2,000 micrograms/100 g body weight. The addition of a surfactant (BL-9) did not increase the effectiveness by the rectal route. When TAP-144 was administered twice a day, the effectiveness was markedly increased by every route. The ED50 values were 0.32 microgram/100 g body weight/time by the subcutaneous route, which was comparable to that of the vaginal route, 14.2 micrograms of the rectal route, and 84.6 micrograms of the nasal route. The addition of the surfactant increased the effectiveness 26 times by the nasal route but not by the rectal route. The pregnancy-terminating effect of TAP-144 was reversed by treatment with progesterone.     

Enzymatic preparation of organometallic compounds with second-order optical nonlinearities

Twelve species of optically active metallocene derivatives having a 4-nitrophenyl group were prepared with horse liver alcohol dehydrogenase- or lipase-catalyzed optical resolution as the key step. The second harmonic generation (SHG) efficiently of these products was measured by the power method using the fundamental light from the Nd:YAG laser. (-)-1- (4-Nitrophenylthio)ethylferrocene (9), (+)-1-(4-nitrophenylthio)ethylruthenocene (16), (+)-1-(4-nitrophenylthio)ethylosmocene (19), (+) -1-(5-nitro-2-pyridylthio)ethylruthenocene (21), and (+) -1-[(4-nitrophenylhydrazono)methyl] -2-methylferrocene (12) showed SHG signals. The highest SHG efficiency was found with (+) -16, being 27 times more intense than the commonly used urea standard.     

Random screening of promoters from Escherichia coli and classification based on the promoter strength

Five hundred fifty DNA fragments 100-500 base pairs in length were cloned from total chromosomal DNA of Escherichia coli, each capable of promoting the synthesis of beta-lactamase when inserted upstream of the ampC structural gene without its own promoter in a promoter-probe plasmid. All clones in this library of putative promoters were classified based on the level of resistance to ampicillin, which ranged from 10 to more than 1,500 micrograms/ml. Most of the higher levels of drug resistance (more than 1,000 micrograms/ml) were due not only to an increase in gene expression but also to an increase in plasmid copy number. The DNA fragments which produced the highest level of drug resistance all mapped at 5.7 min on the E. coli chromosome and shared the same nucleotide sequence. In these fragments, a strong promoter was found, which carries an up stream AT-rich sequence in addition to -35 and -10 signals of the promoter consensus.     

Herpangina surveillance in Japan, 1982-1989. A report of the national epidemiological surveillance of infectious agents in Japan.

In Japan, herpangina cases increase every summer with an incidence peak in July. During the past eight years from January, 1982 to December, 1989, a total of 3,974 viruses from herpangina cases were reported from 47 participating laboratories, and coxsackie A (CA) viruses accounted for most of them, 3,055 (76.9%). The major types associated with herpangina were, in order of frequency, CA4, 10, 5, 6, 2 and 3, representing 87.2%-80.8% of total isolations reported for each respective type in this period. Eighty-four point four percent of the total virus isolations were from children at four years of age or younger. More than 80% of total CA virus isolations were from nasopharyngeal specimens and nearly 90% of the viruses were isolated in mice.     

Comparison of cytochrome P-450 species which catalyze the hydroxylations of the aromatic ring of estradiol and estradiol 17-sulfate

For identification of microsomal cytochrome P-450 (P-450) enzymes which catalyze 2- or 4-hydroxylations of estrogens in the rat liver, estradiol (E₂) and estradiol 17-sulfate (E₂-17-S) were selected as the substrates and incubated with various kinds of purified P-450 enzymes: PB-1, PB-2, PB-4 and PB-5 obtained from phenobarbital-treated male rats (Sprague-Dawley); MC-1 and MC-5 from 3-methylcholanthrene-treated male rats; and UT-1, UT-2, UT-4 and UT-5 from untreated animals. The reactions were carried out under the P-450-reconstructed system, and the resulting products were determined by HPLC using electrochemical detection. All the enzymes tested were shown to have varying degrees of catalytic activities for 2-hydroxylation of the two substrates; UT-1 and UT-2 had the highest activity. Of the induced P-450 enzymes, PB-2 and MC-1 showed fairly high catalytic activity for 4-hydroxylation of E₂. The P-450 enzymes obtained from the untreated male rats, especially UT-4, showed the highest catalytic activity for 4-hydroxylation of the two substrates. From these results and also from kinetic experiments, the P-450 enzymes which catalyze 2- and 4-hydroxylations of estrogen were considered to be different species. A part of E₂ was converted to such metabolites as estrone and those having a hydroxyl group at positions 6β, 15 or 16, each production of which was estimated to be catalyzed by single or multiple P-450s.     

Poliovirus surveillance: isolation of polioviruses in Japan, 1980-1991. A report of the National Epidemiological Surveillance of Infectious Agents in Japan.

This report presents an overall distribution of poliovirus isolations in Japan, where poliomyelitis has been under control over two decades as a result of legal administration of two doses of the trivalent live oral poliovirus vaccine of the Sabin strains (OPV) to children under 48 months of age. During the past 12 years from 1980 through 1991, a total of 1,126 poliovirus isolations from humans and 268 isolations from sewage/river water were reported by respectively 49 and nine of the participating laboratories. Type 2 was most frequently isolated from children after administration of one dose of OPV, followed by type 1 and type 3. On the contrary, after the second dose of OPV, the rate of isolation of type 3 exceeded those of type 2 and type 1. Seasonal and age distribution of poliovirus isolations from both humans and sewage/river water paralleled the OPV vaccination schedule in Japan. One percent of the isolations were, however, from infants younger than the vaccination-scheduled ages and 5% were from children older than those ages, including one each from 15 and 16 years olds. The data indicate that the poliovirus has silently been disseminated from vaccinated children to others and the community, thus suggesting repeated transmission of the viruses. The fact that some elder children had poliovirus colonization in their alimentary tracts indicates a potential risk of infection of such a population when exposed to a wild virus and of becoming a source of transmission to others.     

Thiobacillus novellus cytochrome c oxidase contains one heme alpha molecule and one copper atom per catalytic unit.

The minimal structural unit of cytochrome c oxidase purified from Thiobacillus novellus was composed of one molecule each of two subunits with molecular masses of 32 and 23 kDa, respectively, and the unit had one molecule of heme a and one atom of copper. In the presence of n-octyl-beta-D-thioglucoside, the oxidase existed as the monomeric form of the unit, while it occurred as the dimeric form of the unit in the presence of Tween 20. The monomeric form showed an active cytochrome c oxidizing activity and reduced molecular oxygen to water with ferrocytochrome c. Namely, it has been shown that the bacterial cytochrome c oxidase with one heme a molecule and one copper atom per molecule can catalyze oxidation of ferrocytochrome c with concomitant reduction of molecular oxygen to water.