Immobilization of nucleoside diphosphatase at its allosteric site using immobilized derivatives of pyridoxal 5'-phosphate

3-O-Immobilized and 6-immobilized pyridoxal 5′-phosphate analogs of Sepharose were bound to the allosteric site of nucleoside diphosphatase with very high affinity. Active immobilized nucleoside diphosphatase was prepared by reduction of the Schiff base linkage between the enzyme and pyridoxal 5′-phosphate bound to Sepharose with NaBH₄. 3-O-Immobilized pyridoxal 5′-phosphate analog gave more active immobilized enzyme than the 6-analog; the immobilized enzyme on the 3-O-immobilized pyridoxal 5′-phosphate analog showed about 90% of activity of free enzyme. The immobilized enzyme thus prepared was less sensitive to ATP, an allosteric effector, and showed a higher heat stability than the free enzyme. When an assay mixture containing inosine diphosphate and MgCl₂ was passed through a column of the immobilized enzyme at 37 °C, inosine diphosphate liberated inorganic phosphate almost quantitatively. Properties of the immobilized enzyme on the pyridoxal 5′-phosphate analog were compared with those of the immobilized enzyme on CNBr-activated Sepharose.     

Test for Selection on Polymorphic Isozyme Genes Using the Population Cage Method

Published experimental data of several species of Drosophila using the population cage method were reexamined. The authors of these works have claimed that selection operates on polymorphic isozyme genes. Since selection coefficients (s) estimated by us for the above data, assuming overdominance, or for some cases, additivity between alleles, were too large (s > 0.1), we conclude that these experimental results do not reflect the effects of the single loci in question; rather, we suggest that careful experimentation and judgment are required for testing with the population cage method whether or not selection actually operates on single genes.     

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.     

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.