Binding of cyanide to cytochrome c' from Chromatium vinosum

Spectroscopic evidence is presented which demonstrates the binding of cyanide to the ferric cytochrome c' from Chromatium vinosum. The cytochrome was shown to bind one equivalent of cyanide with an equilibrium constant of 2.1 X 10(4) at pH 7.0 and 25 degrees C. This finding represents the first observation of the binding of an anionic ligand to the heme iron in a ferric cytochrome c'. These results suggest that the binding site of the ferric Chromatium cytochrome c' may be significantly more accessible than previously indicated.     

Isolation of Desulfuromonas acetoxidans cytochrome c-551.5 from the mixed culture ‘Chloropseudomonas ethylica’

The mixed culture ‘Chloropseudomonas ethylica’ strain 2K has been grown on a medium which enhanced the yield of cytochrome c-551.5 from Desulfuromonas acetoxidans. The cytochrome was purified to homogeneity and an isoelectric point of 8.40 was determined. A determination of the amide content indicated that the cytochrome contains two more amides than previously reported.     

Effect of Lincocin Treatment on the Greening Process in Bean (Phaseolus vulgaris) Leaves

The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –¹⁴CO₂ fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes.     

Spectroscopic properties of low-spin ferrous heme complexes and hemeproteins at 77degrees K.

The low temperature optical spectra in the region of the Q₀₀ (α-band) and Q₀₁ (β-band) transitions of model heme complexes for $\text{b}$- and c-type cytochromes were measured and the results discussed in terms of the similarities and differences to the spectra of horse heart cytochrome $\text{c}$ and other hemeproteins. Comparisons of the resolved vibronic components of the Q₀₁ and β′ bands were made to the recent resonance Raman spectra of hemeproteins. Tentative assignment of the β′ band to Q₀₂ type transitions has been proposed.     

UBE1L2, a novel E1 enzyme specific for ubiquitin

UBE1 is known as the human ubiquitin-activating enzyme (E1), which activates ubiquitin in an ATP-dependent manner. Here, we identified a novel human ubiquitin-activating enzyme referred to as UBE1L2, which also shows specificity for ubiquitin. The UBE1L2 sequence displays a 40% identity to UBE1 and also contains an ATP-binding domain and an active site cysteine conserved among E1 family proteins. UBE1L2 forms a covalent link with ubiquitin in vitro and in vivo, which is sensitive to reducing conditions. In an in vitro polyubiquitylation assay, recombinant UBE1L2 could activate ubiquitin and transfer it onto the ubiquitin-conjugating enzyme UbcH5b. Ubiquitin activated by UBE1L2 could be used for ubiquitylation of p53 by MDM2 and supported the autoubiquitylation of the E3 ubiquitin ligases HectH9 and E6-AP. The UBE1L2 mRNA is most abundantly expressed in the testis, suggesting an organ-specific regulation of ubiquitin activation.     

Lecithotrophic development and metamorphosis in the Indo-West Pacific brittle star Ophiomastix venosa (Echinodermata: Ophiuroidea)

Summary

The larval development of the ophiocomid ophiuroid Ophiomastix venosais described using SEM. The gastrula transforms into a uniformly ciliated early larva which progressively changes into a lecithotrophic late premetamorphic larva with a continuous bilateral ciliated band. This stage is short-lived and equivalent to a highly reduced ophiopluteus. Comparisons between O. venosa and other ophiuroid species whose development has been investigated suggest that, whatever the developmental mode (lecithotrophic or planktotrophic), a pluteus stage always occurs in ophiuroids with planktonic development. Two metamorphic stages were identified, the late metamorphic larva differing from the early one by the closure of the larval mouth. The appearance of the permanent mouth marks the end of the metamorphosis. The postlarva still possesses remnants of larval features. The transformation of the reduced ophiopluteus into a barrel-shaped metamorphic larva with transverse ciliated bands, a vitellaria larva, is followed. The possible occurrence of a unique type of metamorphic larva in non-brooding ophiuroids is discussed. Verification of this, however, needs further SEM investigations on metamorphic larva from species having “regular” planktotrophic development.     

Degradation of the cyclic AMP antagonist prostaglandylinositol cyclic phosphate (cyclic PIP) by dephosphorylation

The cAMP antagonist, prostaglandylinositol cyclic phosphate (cyclic PIP), is synthesized from prostaglandin E and activated inositol phosphate. From various tissues only that amount of cyclic PIP can be isolated that constitutes the difference between synthesis and degradation. In order to overcome this drawback, the cyclic PIP degrading enzyme or enzymes had to be characterized prior to searching for inhibitors. Cyclic PIP degrading activities have been found in all rat tissues tested, and are lowest in brain (380 pmol x min(-1) x g(-1) wet weight) and highest in liver (1460 pmol x min(-1) x g(-1) wet weight). They are associated primarily with particulate structures of the cells, but not with the plasma membrane. There appear to be at least two different enzymatic activities involved in the degradation of cyclic PIP, because there are two pH-optima, one between pH 7 and 8 and another between pH 4 and 5. It is assumed that these activities are located in microsomes and lysosomes. Because prostaglandylinositol is the final product obtained in the degradation of cyclic PIP, a phosphodiesterase and a phosphatase should be involved, which could not yet be identified individually. Like alkaline phosphatase, cyclic PIP-degrading enzymes require Mg2+ and they are inhibited by heavy metal ions such as mercuric and copper chloride, by sodium fluoride and interestingly, by prostaglandins.     

Higher Lipoprotein (a) Levels Are Associated with Better Pulmonary Function in Community-Dwelling Older People – Data from the Berlin Aging Study II

Reduced pulmonary function and elevated serum cholesterol levels are recognized risk factors for cardiovascular disease. Currently, there is some controversy concerning relationships between cholesterol, LDL-cholesterol, HDL-cholesterol, serum triglycerides and lung function. However, most previous studies compared patients suffering from chronic obstructive pulmonary disease (COPD) with healthy controls, and only a small number examined this relationship in population-based cohorts. Moreover, lipoprotein a [Lp(a)], another lipid parameter independently associated with cardiovascular diseases, appears not to have been addressed at all in studies of lung function at the population level. Here, we determined relationships between lung function and several lipid parameters including Lp(a) in 606 older community-dwelling participants (55.1% women, 68±4 years old) from the Berlin Aging Study II (BASE-II). We found a significantly lower forced expiration volume in 1 second (FEV1) in men with low Lp(a) concentrations (t-test). This finding was further substantiated by linear regression models adjusting for known covariates, showing that these associations are statistically significant in both men and women. According to the highest adjusted model, men and women with Lp(a) levels below the 20^th percentile had 217.3ml and 124.2ml less FEV1 and 239.0ml and 135.2ml less FVC, respectively, compared to participants with higher Lp(a) levels. The adjusted models also suggest that the known strong correlation between pro-inflammatory parameters and lung function has only a marginal impact on the Lp(a)-pulmonary function association. Our results do not support the hypothesis that higher Lp(a) levels are responsible for the increased CVD risk in people with reduced lung function, at least not in the group of community-dwelling older people studied here.