An anti-Bcl-2 antibody prevents 2-deoxy-D-ribose-induced apoptosis in the IPLB-LdFB insect cell line

Confocal microscopy reveals that the anti-Bcl-2 antibody (pAb) is able to diffuse across the plasma membrane of the fat body cell line IPLB-LdFB from the insect Lymantria dispar, demonstrating the presence of Bcl-2-like molecules in the cytoplasm. Immunoperoxidase procedure confirms the cellular localization. Furthermore, an immunoprecipitation corresponding to a molecular weight of 29 KDa is observed with western blot analysis using the anti-Bcl-2 pAb. Cytofluorimetric experiments show that anti-Bcl-2 pAb counteracts 2-deoxy-d-ribose-induced apoptosis and provokes morphological changes in the insect cell line, i.e. a reduction in cell size, the disappearance of the vacuola and changes in shape. At the same time, the antibody provokes mitochondrial membrane depolarization, and N-acetyl-l-cysteine is unable to reconstitute the physiological conditions. The present findings suggest that Bcl-2-like proteins play a main role in maintaining of the integrity of cellular components, e.g. mitochondria, rather than in controlling programmed cell death. Received 23 January 2001; received after revision 1 March 2001; accepted 1 March 2001     

Prostaglandin A2 (PGA2) increases the coronary vascular resistance in the guinea-pig isolated heart preparation

Summary Prostaglandin A₂ (PGA₂) in concentrations of 1.5·10^–8 to 3·10^–6 M was found to produce concentration-dependent increase in the coronary vascular resistance of the guinea-pig isolated heart without alterations in myocardial contractile force and oxygen consumption.Supported by the Deutsche Forschungsgemeinschaft.     

Measurement of tissuepCO2 in the brain

Zusammenfassung Der mittlerepCO₂ in der Gehirnrinde von Katzen wurde mittels einer neuen Elektrode kontinuierlich registriert. Es wird ein kurzer Bericht über die Messbedingungen, nebst Beispielen vonpCO₂-Veränderungen bei verschiedenen Funktionszuständen, gegeben.     

Effects of Mn2+ and Mg2+ on the pigeon liver pyruvate kinase

Riassunto Mn²⁺ and Mg²⁺ attivano la piruvato cinasi di fegato di piccione in maniera distinta. In presenza di basse concentrationi di fosfoenolpiruvato Mn⁺ é piú efficace di Mg²⁺ ed é attivatore dell'enzima saturato da Mg²⁺. Piruvato cinasi (EC 2.7.1.40).

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This work was supported by a grant from the Consiglio Nazionale delle Ricerche, Roma, Italia.Silvia Baldi is a fellow of the Italian C.N.R.     

Effects of N2, O2'-dibutyril cyclic GMP on the nucleoside phosphotransferase activity of the retina of the chick embryos.

In the retina of the chick embryo, 2 different forms of nucleoside phosphotransferase take part in the phosphorylation of thymidine. One is an unstable form with higher molecular weight. The other with lower m. wt is a stable form. This paper shows that N2,O2'-dibutyril cyclic GMP causes a marked decrement of the activity of the unstable nucleoside phosphotransferase.     

Two NADH2 dehydrogenases in the basidiomyceteOudemansiella mucida

Zusammenfassung In der BasidiomyceteOudemansiella mucida (Schr. ex Fr.) Höhnel wurde eine NADH₂-Dichlorophenolindophenol-Dehydrogenase und eine NADH₂-Menadion-Triphenyltetrazoliumchlorid-Dehydrogenase gefunden. Beide Enzyme unterscheiden sich durch ihre pH-Abhängigkeit, Aktivität und Eluierbarkeit.     

Structural differences between somatic H2B and testis-specific TH2B histones of the rat

Testis-specific histone TH2B from rat testis showed a very similar tryptic map to somatic H2B from rat liver, indicating a common evolutionary origin. However, 5 peptide differences were detected between the 2 proteins, and the amino acid compositions of these distinctive peptides were determined.     

Structural differences between somatic H2B and testis-specific TH2B histones of the rat

Summary Testis-specific histone TH2B from rat testis showed a very similar tryptic peptide map to somatic H2B from rat liver, indicating a common evolutionary origin. However, 5 peptide differences were detected between the 2 proteins, and the amino acid compositions of these distinctive peptides were determined.Supported by Grant 780-0609 from the Ford Foundation.     

Ferrochelatase at the millennium: structures, mechanisms and [2Fe-2S] clusters

Ferrochelatase (E.C. 4.99.1.1, protoheme ferrolyase) catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme (heme). In the past 2 years, the crystal structures of ferrochelatases from the bacterium Bacillus subtilis and human have been determined. These structures along with years of biophysical and kinetic studies have led to a better understanding of the catalytic mechanism of ferrochelatase. At present, the complete DNA sequences of 45 ferrochelatases from procaryotes and eucaryotes are available. These sequences along with direct protein studies reveal that ferrochelatases, while related, vary significantly in amino acid sequence, molecular size, subunit composition, solubility, and the presence or absence of nitric-oxide-sensitive [2Fe-2S] cluster.