Molecular cloning of cDNA encoding the phenol/aryl form of sulfotransferase (mSTp1) from mouse liver

The cDNA sequence of the mouse liver phenol/aryl form of sulfotransferase (mSTp1) has been determined. The cloned cDNA consists of 1269 base pairs (bp) and contains an 897 nucleotide open reading frame (ORF) beginning at nucleotide 65, which encodes a 298 amino acid polypeptide of 34.7 kDa. Alignment of mSTp1 to other sulfotransferases shows overall identities of 87% to r-STp, 37% to r-STa, 48% to r-STe, 51% to b-STe, and 37% to h-STa, at the deduced amino acid level.

Multicellular oxidant defense in unicellular organisms

Although catalase is thought to be a major defense against hydrogen peroxide (H2O2), the catalase activity within individual Escherichia coli fails to protect against exogenous H2O2. Contrary to earlier reports, we find that dilute suspensions of wild-type and catalase-deficient E. coli are identical in their sensitivity to H2O2, perhaps because even wild-type, catalase-positive E. coli cannot maintain an internal/external concentration gradient of this highly diffusible oxidant. However, concentrated suspensions or colonies of catalase-positive E. coli do preferentially survive H2O2 challenge and can even cross-protect adjacent catalase-deficient organisms. Furthermore, high-density catalase-positive--but not catalase-negative--E. coli can survive and multiply in the presence of competitive, peroxide-generating streptococci. These observations support the concept that bacterial catalase may defend colonial, but not individual, E. coli against environmental H2O2. Group protection by the activity of enzymes that mitigate oxidative stress may have been a driving force in the evolution of multicellular organisms.

Molecular cloning of the alcohol/hydroxysteroid form (hSTa) of sulfotransferase from human liver

A cDNA encoding the human alcohol/hydroxysteroid sulfotransferase (h-ST-a), which catalyzes the sulfo-conjugation of many drugs and hormones, was isolated from a human liver cDNA library using a rat STa (rSTa) cDNA probe. The cDNA, designated as hSTa, consists of 1069 base pairs (bp) and contains an 855-nucleotide open reading frame beginning at nucleotide 65, which encodes a 285 amino acid polypeptide of 33.76 kDa. A second cDNA clone (1563 bp) was truncated 5' at nucleotide 231 (lacking the first 15 amino acids) with identical coding region, however, it had a much longer 3' untranslated region (UTR). Both clones contained a short segment of poly(A)+ tail. Northern blot analysis of an adult human liver showed that there are at least 2 mature mRNA with sizes ranging from approximately 1.1 kb to 1.7 kb, verifying the authenticity of the obtained cDNA clones. From the sequence alignment, the hSTa shares 62%/74%, 39%/59%, 35%/48%, 36%/54% identity with rSTa, rSTp (phenol), rSTe (estrogen), and bovine STe (bSTe) at the deduced amino acid and DNA levels, respectively, indicating that there are at least three subfamilies (alcohol, phenol and estrogen) of genes that encode for sulfotransferases in mammals.

The cytosolic components of the respiratory burst oxidase exist as a M(r) approximately 240,000 complex that acquires a membrane-binding site during activation of the oxidase in a cell-free system

Sodium dodecyl sulfate (SDS) treatment of a mixture of cytosol and plasma membranes from resting neutrophils resulted in the activation of the respiratory burst oxidase, a complicated enzyme that catalyzes the production of O2- from NADPH and oxygen. Activation was accompanied by translocation to the plasma membranes of the oxidase components p47phox and p67phox, which in resting cytosol were found in a M(r) approximately 240,000 complex. This translocation, which appeared to take place without a major change in the size of the cytosolic complex, did not occur if the membranes lacked cytochrome b558, and was inhibited by the peptide PRGV-HFIFNK, a sequence found near the carboxyl terminus of cytochrome b558 that was known from earlier work to inhibit O2- production by the cell-free system (Rotrosen, D., Kleinberg, M. E., Nunoi, H., Leto T., Gallin, J. I., and Malech H. L. (1990) J. Biol. Chem. 265, 8745-8750). Cytosols pretreated with the cross-linking agents 3,3'-dithiobis(sulfosuccinimidyl) propionate (DTSSP) (cleavable by 2-mercaptoethanol) and bis-(sulfosuccinimidyl) suberate (not cleavable by 2-mercaptoethanol) lost most of their ability to support O2- production in the cell-free system, and oxidase components from DTSSP-treated cytosol failed to translocate to the plasma membrane. When DTSSP-treated cytosols were incubated with 2-mercaptoethanol, however, both O2- production and translocation were partly restored, indicating that the functional impairment in DTSSP-treated cytosols was probably due at least in part to a restriction in the conformational mobility of the cross-linked peptide chains in the approximately 240,000 complex. These findings provide further support for the idea that the cytosolic components of the respiratory burst oxidase exist in the form of a approximately 240,000 complex, and suggest that the exposure of this complex to SDS induces a structural change that may or may not be associated with the loss of an inhibitory subunit too small to cause a detectable change in the size of the complex. This SDS-induced change allows translocation to take place by creating a membrane-binding site on the surface of the complex.

Random mutagenesis of Schizosaccharomyces pombe SRP RNA: lethal and conditional lesions cluster in presumptive protein binding sites

Signal recognition particle (SRP), a ribonucleoprotein composed of six polypeptides and one RNA subunit, serves as an adaptor between the cytoplasmic protein synthetic machinery and the translocation apparatus of the endoplasmic reticulum. To begin constructing a functional map of the 7SL RNA component of SRP, we extensively mutagenized the Schizosaccharomyces pombe SRP7 gene. Phenotypes are reported for fifty-two mutant alleles derived from random point mutagenesis, seven alleles created by site-directed mutagenesis to introduce restriction sites into the SRP7 gene, nine alleles designed to pinpoint conditional lesions, and three alleles with extra nucleotides inserted at position 84. Our data indicate that virtually all single nucleotide changes as well as many multiple substitutions in this highly structured RNA are phenotypically silent. Six lethal alleles and eleven which result in sensitivity to the combination of high temperature and elevated osmotic strength were identified. These mutations cluster in conserved regions which, in the mammalian RNA, are protected from nucleolytic agents by SRP proteins. The effects of mutations in the presumptive binding site for a fission yeast SRP 9/14 homolog indicate that both the identity of a conserved residue and the secondary structure within which it is embedded are functionally important. The phenotypes of mutations in Domain IV suggest particular residues as base-specific contacts for the fission yeast SRP54 protein. A single allele which confers temperature-sensitivity in the absence of osmotic perturbants was identified in this study; the growth properties of the mutant strain suggest that the encoded RNA is somewhat defective even at the permissive temperature, and is most likely unable to correctly assemble with SRP proteins at the nonpermissive temperature.

Biochemical characterization and time-course analysis of Lymantria dispar nuclear polyhedrosis virus with monoclonal antibodies

Hybridoma cell lines secreting monoclonal antibodies (MAbs) specific to a 31,000 molecular weight viral protein or a 31,000 molecular weight polyhedrin protein of Lymantria dispar nuclear polyhedrosis virus (LdNPV) were developed. The two polypeptides were shown to be different by comparing their amino acid compositions. Immuno-electron microscopy was used to verify specific binding of the MAbs to their respective targets. Specific MAbs were used to develop an ELISA procedure to monitor the development of LdNPV virus and polyhedrin in vivo. Results indicated that in hemolymph of larvae fed 10(6) polyhedral inclusion bodies, the concentration of virus began to increase 16 h after inoculation and continued to increase for the next 5 days. By 36 h, the concentration of polyhedrin increased and was maintained at a high level in the later stages of infection. One-third of this group of infected larvae survived the infection. In these individuals, the concentrations of virus and polyhedrin declined to a low level 5 days after infection. This suggests the presence of a host mechanism for clearing the virus from the hemolymph.

[Electron microscopic observations on Pseudomonas cocovenenans]

A strain of food-poisoning bacterium has been isolated by Jin Jiexiang (1963) in China from the fermented cornflour that has gone bad. These pathogenic microorganism has been identified and named Pseudomonas by Zhao Naixin in 1988, which is the same species as P. cocovenenans. The characteristics of them were conformed to these of the species P. cepacia of section 2 of the genus Pseudomonas. In view of the fact that the fine structures of the above mentioned three strains of Pseudomonas have not been described yet, we decided to observe them with electron microscope. Results indicate there are many things in common among the three strains, such as: appearing short rods, 0.6-0.8 microns in diameter by 1.5-2.0 microns in length, one polar multiflagella; non-pili, non-capsules, non-endospores; containing intranuclear inclusions (electron-dense bodies or concentric laminae bodies), accumulating intracytoplasmic PHB granules; forming filaments, minicells and bizarrecells; producing extracellular cellulose-like materials by the three strains have not been reported previously.

Species- and infective stage-specific monoclonal antibodies to Leishmania major produced by an in vitro immunization method

Monoclonal antibodies specific to the infective-stage promastigotes of Leishmania major are needed for developing rapid diagnostic assays of infected sand flies. An in vitro immunization protocol was applied for the production of monoclonal antibodies using small amounts of L. major. Infective-stage promastigotes were isolated from sand flies (Phlebotomus papatasi) 7-10 days after infection and used as antigen for immunization. Two weeks after a primary immunization, murine splenocytes were removed and immunized in vitro with antigen in murine EL-4 thymoma cell conditioned medium. Three fusions were performed using X63-Ag.653 myeloma cells as fusion partners and two fusions were performed using FOX-NY cells. Antibodies specific to promastigotes were detected using an indirect enzyme-linked immunosorbent assay (ELISA). Initially 56 monoclonal antibodies were selected, and their species and stage specificity were determined using both an ELISA and an indirect fluorescent antibody assay (IFA). Twelve monoclonal antibodies showed species specificity to L. major when tested against four sympatric species of Leishmania. Four other monoclonal antibodies showed species and infective-stage specificity to L. major promastigotes. When tested in immunoblots, all four species- and stage-specific monoclonal antibodies bound to five protein bands that were unique to the infective-stage promastigotes.

Photoperiodic diapause in Drosophila melanogaster involves a block to the juvenile hormone regulation of ovarian maturation

Females of Drosophila melanogaster held under short-day photoperiods at a moderately low temperature (12 degrees) enter a state of ovarian diapause in which yolk deposition in the oocytes is suspended (D. S. Saunders, V. C. Henrich, and L. I. Gilbert, Proc. Natl. Acad. Sci. USA 86, 3748-3752, 1989). An enzyme-linked immunosorbent assay (ELISA) using polyclonal antibodies raised against D. melanogaster yolk polypeptides (YPs) showed that diapausing flies synthesize and accumulate YPs in the hemolymph, but very little in the ovary. Nondiapausing females at the same temperature but at long days, and short-day flies in which diapause was broken by an upshift in temperature or topical application of juvenile hormone (JH), showed enhanced titers of YPs in the ovaries, suggesting stimulating uptake. Determinations of juvenile hormone bisepoxide (JHB3) and JH III synthesis in vitro by single excised corpora allata showed that glands from nondiapausing flies or corpora allata from flies in which diapause had been broken synthesized JH at a rate about four times higher than glands from diapausing flies. Corpora allata incubated in medium supplemented with farnesoic acid showed an increase in the rate of JH synthesis, but the increase was relatively greater with corpora allata from nondiapausing flies. Glands from diapausing flies presented the appearance of newly emerged or "immature" glands. Ovarian diapause is terminated at 12 degrees LD 10:14 in 7 days following topical application of either JH III or JHB3 at a concentration of about 0.5 micrograms per fly, diapause termination being expressed by an increased rate of vitellogenesis and by an increase in the number of fully developed eggs per vitellogenic female. It is concluded that the short-day-elicited diapause in D. melanogaster results from a "block" to the JH-stimulated uptake of yolk proteins from the hemolymph, caused by a reduced rate of JH synthesis by the corpus allatum. Photoperiodic regulation of the corpus allatum may be mediated via the brain.

[Separation and purification of the toxic protein of Bacillus sphaericus Ts-1]

Bacillus sphaericus strain Ts-1 is highly insecticidal to larvae of the mosquito. It's insecticidal component is toxic proteins. The toxin was extracted from spore-crystal complexes by disruption in a Sonicator Cell Disruptor Model W-220F followed by treatment with 0.05 mol/L NaOH. Fraction recovered from chromatography of the spore-crystal complexes on column of Sephadex G-200 were assayed against mosquito larvae and the toxic fractions from gel chromatography were subjected to SDS-PAGE. The toxic proteins in B. sphaericus Ts-1 spore-crystal complex migrated in position corresponding to 42kD and 43kD. Bioassay of the two purified proteins prepared by PAGE indicated that they were all toxic to mosquito larvae. Toxic protein was further purified by DEAE-cellulose chromatography. The toxic protein with a molecular weight of 42kD was obtained.

Heat treatment of cytochrome c oxidase perturbs the CuA site and affects proton pumping behavior

It has been previously reported that mild heat treatment (43 degrees C for ca. 60 min) abolishes the proton pumping activity of cytochrome c oxidase while leaving the oxidase activity and cytochromes a and a3 unperturbed [Sone, N., & Nicholls, P. (1984) Biochemistry 23, 6550-6554]. We herein describe the effects of this heat treatment on the electron paramagnetic resonance (EPR) and optical absorption signatures of the redox-active metal centers in the enzyme. We find that heat treatment of the oxidized enzyme causes a local structural perturbation at the CuA site. After heat treatment, the enzyme sample contains three subpopulations, each of which has a different structure at CuA. These include (i) native CuA, (ii) a type 2 copper species similar to the one produced by chemical modification by p-(hydroxymercuri)benzoate (pHMB) [Gelles, J., & Chan, S. I. (1985) Biochemistry 24, 3963-3972], and (iii) a novel type 1 copper species. In addition to changes at the CuA site, we find that heat treatment results in accelerated cyanide binding and the removal of subunit III. If the cytochrome c oxidase is heat treated while fully reduced, none of these changes are observed except for subunit III depletion. Furthermore, partial (CO mixed-valence derivative) reduction of the enzyme as well as ligand binding to cytochrome a3 also protects the enzyme against the heat-induced changes, indicating that the oxygen binding site plays a role in stabilizing the CuA site against structural perturbations.(ABSTRACT TRUNCATED AT 250 WORDS)

Hb F-Xin-Su or A gamma I73(E17)Asp----His: a new slow-moving fetal hemoglobin variant

A slow-moving gamma chain variant was discovered in the cord blood of an infant born to parents of the Han nationality from Jiangsu. The variant, which migrated electrophoretically at alkaline pH between Hb A and Hb D, was characterized by an Asp----His substitution at gamma 73, while residues gamma 75 and gamma 136 were occupied by Ile and Ala, respectively. As the A gamma T-chain was also present, this baby has two types of abnormal gamma-chain. The variant was named Hb F-Xin-Su.

Hb F-Xinjiang or A gamma T25(B7)Gly----Arg: a new slow-moving unstable fetal hemoglobin variant

This report describes a new fetal hemoglobin variant, Hb F-Xinjiang, which was observed in a newborn baby of the Han nationality. Its electrophoretic mobility at pH 8.6 was slower than that of Hb D. Structural analyses identified the variant as A gamma T25(B7)Gly----Arg. Heat stability test showed that the variant was unstable.

Adverse reactions associated with pentamidine isethionate in AIDS patients: recommendations for monitoring therapy

Since pentamidine has become commercially available, there is renewed interest in using it as the initial treatment for Pneumocystis carinii pneumonia (PCP) in AIDS patients. We reviewed the use of pentamidine in 24 patients with PCP to gain information on the prevalence and severity of adverse effects from this drug. Twenty out of twenty-four patients (83 percent) experienced some kind of adverse effect. Hepatic abnormalities (58 percent), nausea and vomiting (46 percent), hypoglycemia (33 percent), azotemia (25 percent), and pain at the injection site (25 percent) were the most frequently seen effects. We recommend monitoring guidelines to be applied during pentamidine therapy based on the observed frequency of specific side effects.

A transforming marker that produces merodiploids with high efficiency and stable transformants with low efficiency in Streptococcus

A mutation (ery-r8) conferring a high level of resistance to erythromycin in the Challis strain of Streptoccus sanguis can be transferred to wild-type erythromycin-sensitive recipients via single molecules of donor DNA. The transformants thus produced are of two types: (1) cells slightly more resistant to erythromycin than wild-type and capable of segregating (at a frequency of 2 X 10(-4)/bacterium/generation) either wild-type or highly-resistant cells like the original donor type; (2) cells phenotypically and genotypically identical to the original donor type. The unstable diploids (ery-r8/+) occur with a frequency equivalent to that obtained with high-efficiency (HE) markers, whereas the stable donor-type (ery-r8) transformants occur with about five hundred times lower frequency. Penetration of the wild-type recipient by more than one molecule of DNA bearing the ery-r8 marker increases by as much as seven times the incidence of stable transformants. UV-irradiation of molecules bearing the ery-r8 marker diminishes their ability to cooperate in producing a stable transformant, although the UV sensitivity of stable transformant production by a single DNA molecule is not different from that of diploid production. Hence, stable transformants do not appear to be produced by a process typical of low efficiency (LE) markers, which are generally highly sensitive to ultraviolet irradiation. Moreover, stable ery-r8 transformants are produced with equally low frequencies in strains of S. pneumoniae that discriminate (hex+) and fail to discriminate (hex--) between HE and LE markers. We postulate that all transformations by the ery-r8 marker result in ery-r8/+ diploids, and that segregation results in the infrequent stable transformants of the original donor type. This hypothesis is supported by the observations that rifampin treatment of ery-r8/+ populations increases the frequency of segregation and similar treatment of wild-type recipients under-going transformation by the ery-r8 marker increases the frequency of stable transformants.--In producing the ery-r8/+ transformant the r8 allele is integrated close to the site of its wild-type homolog, since single molecules of DNA from this transformant can be shown to carry both alleles. Segregation of either the ery-r8 or + allele is not detectably enhanced by acridine orange or thymidine deprivation.--The ery-r8 marker occurs close to a site of mutation (ery-r2) which confers erythromycin resistance upon ribosomes. When the r2 and r8 markers are jointly transferred, ery-r2-r8/+ genomes are produced in which the r2 marker is stably integrated but the r8 marker is unstably adjoined to its wild-type homolog. Thus, the duplicated region can be quite short. When the ery-r8 marker is stably integrated, the region of the marker is refractory to subsequent transformation. Markers with properties like ery-r8 are not particularly rare, being found with a frequency of about 4% among spontaneous mutations to erythromycin resistance.

Specific effects of heating of transformable streptococci on their ability to discriminate between homospecific, heterospecific, and hybrid deoxyribonucleic acid

Heating competent bacteria of the Challis strain of Streptococcus at a temperature of 48 C causes them to lose their transformability and mainfest a slight retardation of growth rate without loss of viability. The heat-induced loss of transformability is due to diminution in the ability of the bacteria to bind deoxyribonucleic acid (DNA) irreversibly. Another effect of heat is upon a step in the transformation process subsequent to binding, a step in which DNA molecules will compete if they multiply infect an unheated cell. Despite the reduction in irreversible binding exhibited by heated cells, competition between DNA molecules to transform these cells is decreased. Neither of these sites affected by heat exhibits any specificity with regard to origin of DNA. Since heat treatment causes a relative stimulation of transformation by heterospecific DNA, a third effect of heat must be envisaged. The amount of heat-induced stimulation is dependent upon the amount of heterospecific material in the transforming DNA. Linkage of heterospecific markers is increased as a consequence of heating the recipients. Transformation by markers of different transforming efficiency in homospecific DNA is also affected by heat treatment in a differential manner. Taken together, these results point to a heat-sensitive intracellular mechanism that recognizes DNA base sequences during transformation. The effect of heat upon discrimination against heterospecific DNA has been found to occur also in the pneumococcus and in Bacillus subtilis.