Interaction of calmodulin with synthetic deletion peptides of melittin

The 26-residue peptide melittin present in bee venom has been shown to bind calmodulin tightly. In this study we synthesized the following series of deletion peptides of melittin by the solid-phase method: Mel12, Mel13, Mel14, Mel15, Mel15F. The results of this study show that the deletion peptides Mel14 and Mel15 have almost the same binding activity as the intact native peptide. Each deletion peptide forms a 1:1 complex with calmodulin according to electrophoresis analysis. When the tryptophanyl residue of Mel15 was replaced by the phenylalaninyl residue, the dissociation constant of the peptide-calmodulin complex increased. This shows the importance of the tryptophanyl residue for binding to calmodulin.

The urban church and cancer control: a source of social influence in minority communities

A study was conducted to examine the efficacy of a church-based model of social influence in improving access to and participation of underserved minority women in a cervical cancer control program. The model expanded on strategies used in previous hypertension control and health promotion research. A total of 24 churches, stratified by faith tradition, were randomly selected to participate in the cancer control program from a pool of 63 churches in a defined geographic area of Los Angeles County, CA. Female parishioners ages 21 years and older were eligible to participate in cervical cancer education sessions, and screening was offered to adult women who had not had Papanicolaou tests within the last 2 years. Church participation rate was 96 percent. Thirty lay health leaders were selected by the clergy to serve as messengers, recruiters, and organizers for their respective congregations. Ninety-seven percent of these lay health leaders participated in two training sessions designed to prepare them for their leadership role. Social support structures such as child care, meals, or transportation for targeted women were organized by lay health leaders in 78 percent of the churches. A total of 1,012 women between the ages of 21 and 89 years attended educational sessions. Forty-four percent of the eligible women were targeted for screening because they had not had a Papanicolaou test within the last 2 years or had never been screened. Black women were 6.6 times more likely than Hispanics to have been screened in the past 2 years. Hispanic women were 4.2 times more likely than African Americans never to have had a Papanicolaou test or been tested in 3 or more years.Overall, 90 percent of the women targeted for screening recruitment presented for tests.Fifty-two percent of the churches initiated cancer control activities by the end of the 2-year period following the culmination of the intervention program.The findings suggest that a church-based model of social influence can leverage the participation of minority women in cervical cancer control, provide access to underserved Hispanic women in particular,and sustain cancer control activities beyond the life of an intervention program.The findings further suggest that a more discrete assessment of screening history may improve the participation levels of African American women, and that the gratis offering of screening services may adversely affect their participation rates.

Mitosis-promoting factor activity of inducer mitotic cells may affect radiation yield of interphase chromosome breaks in the premature chromosome condensation assay

We measured mitosis-promoting factor (MPF) activity in two cell lines, CHO and HeLa, extensively used at mitosis as inducers in the assay of premature chromosome condensation to study the yield and the repair kinetics of radiation damage in interphase chromosomes of diverse cell lines. We found a 2.5-fold higher MPF activity in HeLa as compared to CHO mitotic cells per mg of crude extract protein. HeLa mitotic cells, when used as inducers of premature chromosome condensation, uncovered two times more interphase chromosome breaks in irradiated, nonstimulated human lymphocytes as compared to CHO mitotic cells. A 2-fold increase in the yield of interphase chromosome breaks with HeLa mitotics was also observed in G1 cells from plateau-phase CHO cultures. Thus, MPF activity may be a contributing factor of the process that transforms radiation-induced DNA damage to chromosome breaks, and subsequently to other types of lethal chromosome aberrations. We speculate that the level and the control in the cell cycle of MPF activity may influence the radiosensitivity of cells to killing. The results strongly suggest that a direct comparison between the yields of interphase chromosome breaks measured in different laboratories may not be possible unless similar inducer cells with similar MPF activity are used.

Energetics of intersubunit and intrasubunit interactions of Escherichia coli adenosine cyclic 3',5'-phosphate receptor protein

Escherichia coli cAMP receptor protein (CRP) regulates the expression of a large number of catabolite-sensitive genes. The mechanism of CRP regulation most likely involves communication between subunits and domains. A specific message, such as the activation of CRP, may be manifested as a change in the interactions between these structural entities. Hence, the elucidation of the regulatory mechanism would require a quantitative evaluation of the energetics involved in these interactions. Thus, a study was initiated to define the conditions for reversible denaturation of CRP and to quantitatively assess the energetics involved in the intra- and intersubunit interactions in CRP. The denaturation of CRP was induced by guanidine hydrochloride. The equilibrium unfolding reaction of CRP was monitored by three spectroscopic techniques, namely, fluorescence intensity, fluorescence anisotropy, and circular dichroism. The spectroscopic data implied that CRP unfolds in a single cooperative transition. Sedimentation equilibrium data showed that CRP is dissociated into its monomeric state in high concentrations of denaturant. Unfolding of CRP is completely reversible, as indicated by fluorescence and circular dichroism measurements, and sedimentation data indicated that a dimeric structure of CRP was recovered. The functional and other structural properties of renatured and native CRP have also been examined. Quantitatively identical results were obtained. Results from additional studies as a function of protein concentration and from computer simulation demonstrated that the denaturation of CRP induced by guanidine hydrochloride proceeds according to the following pathway: (CRP2)Native<-->2(CRP)Native<-->2(CRP)Denatured. The delta G values for dissociation (delta Gd) and unfolding (delta G(u)) in the absence of guanidine hydrochloride were determined by linear extrapolation, yielding values of 12.0 +/- 0.6 and 7.2 +/- 0.1 kcal/mol, respectively. To examine the effect of the DNA binding domain on the stability of the cAMP binding domain, two proteolytically resistant cAMP binding cores were prepared from CRP in the presence of cAMP by subtilisin and chymotrypsin digestion, yielding S-CRP and CH-CRP, respectively. Results from an equilibrium denaturation study indicated that the denaturation of both CH-CRP and S-CRP is also completely reversible. Both S-CRP and CH-CRP exist as stable dimers with similar delta Gd values of 10.1 +/- 0.4 and 9.5 +/- 0.4 kcal/mol, respectively. Results from this study in conjunction with crystallographic data [McKay, D. B., Weber, I. T., & Stietz, T. A. (1982) J. Biol. Chem. 257, 9518-9524] indicate that the DNA binding domain and the C-helix are not the only structural elements that are responsible for subunit dimerization.(ABSTRACT TRUNCATED AT 400 WORDS)

Vaginal reconstruction with an island flap of the inferior epigastric vascular pedicle

This paper presents a new method of vaginal reconstruction. On the basis of anatomic study, we designed an island flap obtained from the upper abdomen to carry the deep inferior epigastric vasculature. At operation, the flap was transferred to the artificial cavity created between the urinary bladder and rectum for vaginal reconstruction. Eight patients received the operation. Complete survival of the flap occurred in seven patients, and one flap failed because of a twist in the flap vascular pedicle. During a follow-up of 6 months to 2 years, it was found that the reconstructed vaginal wall was not only soft but also elastic, and the patients were able to have a satisfying sexual life after marriage.

Crystal structure of the HhaI DNA methyltransferase complexed with S-adenosyl-L-methionine

The first three-dimensional structure of a DNA methyltransferase is presented. The crystal structure of the DNA (cytosine-5)-methyltransferase, M.HhaI (recognition sequence: GCGC), complexed with S-adenosyl-L-methionine has been determined and refined at 2.5 A resolution. The core of the structure is dominated by sequence motifs conserved among all DNA (cytosine-5)-methyltransferases, and these are responsible for cofactor binding and methyltransferase function.

Mapping of a surface-exposed B-cell epitope to the variable sequent 3 of the major outer-membrane protein of Chlamydia trachomatis

A B-cell epitope, AEFPLDIT, was located to the variable sequent 3 of the major outer-membrane protein (MOMP) using the monoclonal antibody L3-1, raised to the Chlamydia trachomatis serovar L3 MOMP. By Western blot and inclusion immunofluorescence assay the monoclonal antibody recognized all the C complex and C-related complex serovars of C. trachomatis, except serovar C. Dot-blot and ELISA data using native elementary bodies indicated that the epitope was surface exposed. The monoclonal antibody, at concentrations of 10 and 100 micrograms per 10(7) chlamydial inclusion-forming units, was able to neutralize the infectivity of chlamydia in an in vivo assay but did not neutralize chlamydia in vitro or in a mouse toxicity assay. A peptide corresponding to the variable sequent 3 has previously been shown to also elicit a T-cell response; thus, careful consideration should be given to inclusion of this region of the major outer-membrane protein in a subunit vaccine.

Identification and characterization of serotype 4-specific antigens of Ureaplasma urealyticum by use of monoclonal antibodies

Monoclonal antibodies against Ureaplasma urealyticum serotype 4 were produced by immunizing BALB/c mice with whole-cell antigens of the U. urealyticum serotype 4 reference strain. Ten monoclonal antibodies differentiated into two groups were found: one group included five monoclonal antibodies recognizing a band in immunoblotting that had a molecular mass of 81 kDa, and a second group included another five monoclonal antibodies recognizing three bands in immunoblotting that had molecular masses of 81, 75, and 71 kDa. Fifteen clinical U. urealyticum isolates were selected for serotyping with serotype 4-specific monoclonal antibodies and polyclonal antisera 1 to 14. The results obtained with polyclonal and monoclonal antibodies suggest the existence of heterogeneity of the serotype antigens among clinical isolates of U. urealyticum serotype 4.

Characterization of a neutralizing monoclonal antibody directed at variable domain I of the major outer membrane protein of Chlamydia trachomatis C-complex serovars

A monoclonal antibody (MAb), C10, that neutralized in vitro the infectivity of serovars C, I, J, and L3 (members of the C and C-related complexes) of Chlamydia trachomatis was identified. Of the 15 major serovars and the mouse pneumonitis strain of C. trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae, which were used as nontreated and heat-treated (56 degrees C, 30 min) antigens in a dot blot assay, only serovars C, I, J, and L3 were recognized with both the native and treated antigens. Western blot (immunoblot) results showed that MAb C10 recognized the major outer membrane protein of these four serovars. Overlapping hexameric peptides corresponding to variable domains (VDs) I, II, III, and IV of the major outer membrane protein of C. trachomatis serovar C were synthesized, and peptide screening showed that MAb C10 mapped to the VD I amino acid sequence VAGLQNDPT. Results of an in vitro neutralization assay correlated with those of the indirect immunofluorescence assay, Western blot, and dot blot assay in that only serovars C, I, J, and L3 were neutralized by MAb C10. In vitro competitive neutralization experiments, using a peptide representing VD I of serovar C to compete with C. trachomatis serovar C for MAb C10 binding, revealed that both serological and neutralizing activities of MAb C10 were inhibited by the VD I peptide. In an in vivo toxicity/infectivity assay using serovar L3 pretreated with MAb C10, there was 100% survival of mice infected with a lethal dose at 48 h. In contrast, the control group, consisting of mice injected with the same dose of L3 pretreated with a MAb that does not recognize L3, had no survivors during a 48-h observation period. In summary, since the surface-exposed contiguous epitope recognized by MAb C10 binds neutralizing antibodies that are subspecies specific for the C and C-related complexes, it should be considered for inclusion in the development of a chlamydial vaccine.

Effects of antibody isotype and host cell type on in vitro neutralization of Chlamydia trachomatis

Monoclonal antibodies (MAbs) E-4, E-21, and DIII A3, which recognize the same or similar overlapping peptides in the variable domain IV of the major outer membrane protein of Chlamydia trachomatis but differ in isotype, were used in a complement-independent (CI) in vitro neutralization assay. These MAbs had previously been shown to neutralize chlamydial infectivity in HeLa 229 cells in a complement-dependent assay. In this report, all three MAbs neutralized chlamydial infectivity in HaK cells in a CI assay. However, when HeLa cells were used as the host cell, MAb E-4 (immunoglobulin G2b [IgG2b]) and MAb DIII A3 (IgG2b) failed to neutralize infectivity, while MAb E-21 (IgG1) neutralized chlamydial infectivity. These findings are consistent with the proposal that because of the presence of Fc gamma RIII receptors, HeLa cells facilitate infectivity and thus block neutralization through the uptake of an IgG2b-chlamydia complex. Since Fc gamma RIII receptors do not bind or bind poorly to IgG1, neutralization of C. trachomatis by MAb E-21 in HeLa cells is also corroborative evidence for the role of Fc gamma RIII receptors in this interaction. A fivefold enhancement of infectivity was seen when 10 and 1 micrograms of MAb E-4 per ml were tested in a CI assay with HeLa cells. In performing CI neutralization synergy studies in HeLa cells with MAbs E-4 and E-21, antagonism between MAbs E-4 and E-21 was observed at MAb E-4 concentrations of 10 and 1 micrograms/ml for all concentrations of MAb E-21 tested (10 to 0.1 micrograms/ml). When HaK cells were used in the same studies, no antagonism between the MAbs was found. In addition, when HeLa cells were used in a CI assay, polyclonal serum raised to a peptide representing variable domain IV of the major outer membrane protein inhibited the neutralizing ability of MAb E-21. The blocking of neutralization and the enhancement of infectivity by chlamydia-specific antibodies seen in this investigation with HeLa cells may have important clinical implications for developing preventive strategies for chlamydial infections.

A simplified methodology for quantitation of butadiene metabolites. Application to the study of 1,3-butadiene metabolism by rat liver microsomes

A rapid, simple extraction and GC assay procedure is described that allows quantitation of micromolar concentrations of butadiene bisoxide and 3-butene-1,2-diol in microsomal suspensions exposed to butadiene. Butane-1,4-diol is used as the internal standard. The recovery of these compounds from aqueous media was almost quantitative, and calibrations for each compound were linear from 10(-6) to 10(-3) M. In this system butadiene monoxide and crotonaldehyde can be rapidly quantitated at micromolar concentration by headspace sampling, using methanol or n-butanol as the internal standard. In addition, the synthesis and chemical characterization of diastereomeric 3,4-epoxybutane-1,2-diols are described. It is demonstrated that the epoxy diol, although not extractable from aqueous solutions by ethyl acetate, can be recovered upon evaporation of aqueous media, followed by ethyl acetate extraction. Direct GC quantitation of the epoxy diol was linear from 10(-5) to 10(-3) M. This procedure facilitated the examination of butadiene metabolism by rat liver microsomes. Exposure of microsomes to butadiene resulted in the NADPH-dependent formation of butadiene monoxide, crotonaldehyde, 3-butene-1,2-diol, and one diastereomer of 3,4-epoxybutane-1,2-diol.

[Conditions for dextranase formation by Paecilomyces lilacinus]

Induced formation conditions of dextranase by Paecilomyces lilacinus were investigated. Effect of various carbohydrates on dextranase formation was examined, dextran was the best C-source and as an inducer. The effect of dextran with different molecular weight (from 17.2 to 1000 kD) on dextranase formation was compared, productivity of dextranase increased with increase of dextran molecular weight. When dextran of 1000 kD was used as C-source. The enzyme formation was 40% higher than that 17.2 kD dextran. When other sugars were separately added to the medium with dextran, the enzyme formation was repressed. Besides C-source, the other optimum conditions of dextranase formation were as follows: N-source, beef peptone; medium initial pH, 6.0-7.0; culture temperature, 28 degrees C; inoculum amount about 10%, and the organism was cultivated for 6 days on 200 r/min shaker in 250 ml flasker with 50 ml medium.

Purification, crystallization, and preliminary X-ray diffraction analysis of an M.HhaI-AdoMet complex

The type-II DNA-(cytosine-5)-methyltransferase M.HhaI was overexpressed in Escherichia coli and purified to apparent homogeneity. The purification scheme exploits a unique high salt back-extraction step to solubilize M.HhaI selectively, followed by FPLC chromatography. The yield of purified protein was 0.75-1.0 mg per gram of bacterial paste. M.HhaI could be isolated in two forms: bound with its cofactor S-adenosylmethionine (AdoMet) or devoid of the cofactor. The AdoMet-bound form was capable of methylating DNA in vitro in the absence of exogenous AdoMet. From kinetic studies of the purified enzyme, values for KmAdoMet (60 nM), KiAdoHye (0.4 nM), and Kcat (0.22 s-1) were determined. The purified enzyme bound with its cofactor was crystallized by the hanging drop vapor diffusion technique. Crystals were of monoclinic space group P2(1) and had unit-cell dimensions of a = 55.3 A, b = 72.7 A, c = 91.0 A, and beta = 102.5 degrees, with two molecules of M.HhaI in each of the two asymmetric units. The crystals diffract beyond 2.5 A and are suitable for structure determination.

Construction and use of lambda PL promoter vectors for direct cloning and high level expression of PCR amplified DNA coding sequences

A set of plasmid vectors which allow single-step cloning and expression of PCR-amplified DNA coding sequences has been constructed. The vectors contain the phage lambda PL promoter, a synthetic translation initiation region (TIR), and convenient cloning sites. The cloning sites provide all or part of an AUG translation initiation codon and facilitate the precise fusion of target DNA sequences to vector transcriptional and translational signals. The vectors were constructed with synthetic TIRs because there is evidence which suggests that the efficiency of the phage lambda cII gene TIR present in the parental vector depends strongly on information contained within the cII N-terminal coding sequence. Bovine brain 14-3-3 eta chain cDNA was PCR-amplified and used to demonstrate the expression capacity of the newly constructed vectors. A significant increase in expression of 14-3-3 protein was observed when synthetic TIRs were used in the place of the cII TIR. Expression levels vary from 15% to 48% of total cell protein. The effects of a reported translational enhancer from phage T7 on expression of the 14-3-3 protein are also discussed. The vectors should be generally useful for high level heterologous protein expression in Escherichia coli.

[Analysis of natural history and long-term follow-up of 59 patients with obliterative pulmonary hypertension (OPH)]

The diagnosis of OPH was made by clinical and hemodynamic data in 59 patients, including 30 cases of unexplained pulmonary hypertension, 26 cases of pulmonary embolism and 3 others. The survival curve showed that the two-year survival rate of the patients was 76.72%, and the five-year rate was 63.37%. The single correlation factors influencing prognosis were the interval from onset of symptoms to diagnosis (course), cardiac function, PaO2, SaO2, cause of disease, pulmonary artery pressure and right atrial pressure. The outcome of long-term treatment (mean 4.2 years) in 15 patients with OPH was as follows: remarkable improvement in 8 cases, amelioration in 3, no change in 2 and deterioration in 2. The total effective rate was 73.33%. The importance of anticoagulant therapy and the use of nifedipine are discussed.

Characterization of the humoral response induced by a peptide corresponding to variable domain IV of the major outer membrane protein of Chlamydia trachomatis serovar E

A 30-amino-acid peptide corresponding to variable domain IV (VD IV) of the major outer membrane protein of Chlamydia trachomatis serovar E was conjugated to keyhole limpet hemocyanin (KLH) and used to immunize mice. The resulting antisera (anti-KLH-VD IV sera) recognized all 15 serovars of C. trachomatis when assayed by indirect immunofluorescence and Western blotting. Probing of overlapping hexameric peptides representing VD IV with mouse anti-KLH-VD IV sera revealed that two main regions of the peptide were recognized by the antisera, the N terminus of the peptide, which contains B-complex-specific epitopes, and the middle region of the peptide, which contains a species-conserved domain. When used in an in vitro neutralization assay, these antisera were able to neutralize mainly serovars in the B complex. These data provide evidence that a linear peptide corresponding to VD IV can induce in vitro protection from C. trachomatis infectivity that is subspecies specific.

Metabolism of trans,trans-muconaldehyde by aldehyde and alcohol dehydrogenases: identification of a novel metabolite

The metabolism of trans,trans-muconaldehyde (MA), a highly reactive alpha,beta-unsaturated dialdehyde, was examined in vitro using purified yeast alcohol and aldehyde dehydrogenases (ADH and ALDH, respectively). In the presence of NAD(+)-fortified ALDH, the mono-oxidation product (acid/aldehyde) was the primary metabolite formed with trace amounts of the dioxidation product (trans,trans-muconic acid). In NADH-fortified reactions with ADH, both the mono- and direduction products (hydroxy/aldehyde and dihydroxy, respectively) were readily detected. Oxidation and reduction products of MA were formed in incubates containing both dehydrogenases together with either NAD+ or NADH. Unexpectedly, an additional metabolite was detected, which was a major product in both NAD(+)- and NADH-fortified systems containing ALDH and ADH in combination and whose formation could be inhibited by pyrazole (an ADH inhibitor). ALDH-mediated oxidation of a synthetic standard of the hydroxy/aldehyde derivative of MA resulted in formation of this new metabolite, which was also a major product formed by rat hepatocytes incubated with MA. Using HPLC/photodiode array detection, the new metabolite was found to cochromatograph and have a uv spectrum identical to that of a synthetic standard of the hydroxy/acid derivative of MA. The metabolite was confirmed as the hydroxy/acid derivative of MA after preparative HPLC, TMS derivatization, and GC/MS analysis. The hydroxy/acid metabolite was not formed during ADH-mediated reduction of the mono-oxidation product of MA, suggesting that this metabolite was formed by yeast dehydrogenases via a primary reduction of MA and subsequent oxidation of the hydroxy/aldehyde to the hydroxy/acid. These data show that the hydroxy/acid derivative is a novel metabolite of MA, which arises from the interaction of both oxidative and reductive routes of metabolism.

Functional and structural mapping of Chlamydia trachomatis species-specific major outer membrane protein epitopes by use of neutralizing monoclonal antibodies

Three monoclonal antibodies (MAbs), E4, L1-4, and L1-24, to the major outer membrane protein (MOMP) of Chlamydia trachomatis were identified that neutralized in vitro the infectivity of members of the B- and C-related complex as well as the mouse pneumonitis strain. MAbs L1-4, L1-24, and E4 gave a strong signal in an indirect immunofluorescence assay and/or Western immunoblot with all serovars of the lymphogranuloma venereum and trachoma biovars and a weak signal with the mouse biovar. In addition, C. psittaci and C. pneumoniae were also weakly recognized by MAbs L1-4 and L1-24. As determined by the technique of pneumoniae were also weakly recognized by MAbs L1-4 and L1-24. As determined by by the technique of overlapping peptides, all three MAbs showed reactivity to variable domain (VD) IV of MOMP. While all three MAbs had different recognition patterns, all strongly bound to the peptides TLNPTI and LNPTIA within the species-conserved region of VD IV. MAb E4 also recognized the peptide SATAIF in the subspecies region of VD IV. Peptides corresponding to VD IV of MOMP were synthesized and used in competitive inhibition experiments to determine the functional location of the epitope recognized by these three MAbs. Both the serological and neutralizing activities of MAb E4 were inhibited by the peptides ATAIFDTTTLNPTIAG and FDTTTLNPTIAG; however, none of the peptides made to the VD IV region blocked the neutralizing activity of MAbs L1-4 and L1-24. Therefore, the neutralizable domain of the epitope recognized by MAb E4 is contiguous and may be an important candidate for inclusion in a subunit vaccine.

[Nuclear DNA assay in gynecologic malignant tumors and its clinical significance]

This paper analyzes the nuclear DNA content in 80 gynecologic tumors by microspectrophotometry and correlates the results of ovarian malignant tumors with the clinico-pathologic features of the tumor. The DNA content and the percentage of nuclei with over octaploid were significantly higher in gynecologic malignant tumors and ovarian germ cell tumors than in gynecologic benign tumors and ovarian epidermic tumors. The percentage of nuclei with over octaploid was significantly higher in advanced than in early tumors. It seems that DNA content assay may be helpful in the pathological diagnosis of gynecologic tumors.