Identification of 2 phosphorylated amino acids in chicken bone phosphoproteins]

Phosphoproteins of Chicken bone have been extracted by 0.5 M EDTA pH 7.5. Their amino acid composition was similar to that of phosphoproteins of other calcified tissues. The crude EDTA extract contained 80 to 90% proteins, only 70% of the total organic phosphorus was bound to the proteins. We have studied and identified two phosphorylated components. o-phosphoserine and o-phosphothreonine have been identified by amino acid analysis at pH 1.7 from a partial acid hydrolysate, and confirmed by the liberation of the parent amino acids after total hydrolysis. In addition, phosphorus was found equimolecular to both of them. The presence of these phosphorylated groups is important for an understanding of the role of these proteins in the mechanism of mineralization.     

New centrally acting drugs: Coumarin derivatives

Riassunto Si descrive una nuova classe di farmaci stimolanti il sistema nervoso centrale, rappresentata dalle aminometilidrossi- e dalle aminometilmetossicumarine N-sostituite.L'attività di questi nuovi composti è inferiore a quella dei corrispondenti isomeri derivati dal cromone e dal flavone.     

Antiviral activity of some derivatives of 2-styrylquinoline

Zusammenfassung In Mäuseversuchen wurde gezeigt, dass gewisse Styrylquinoline in vivo eine Wirkung gegen Semliki-Forest-Virus haben.     

New tigliane and daphnane derivatives fromPimelea prostrata andPimelea simplex

Summary From the methanol extract ofPimelea prostrata, prostratin (I) and 2 autoxidation products have been isolated. They are tigliane derivatives and relatively nonirritant on the mouse ear. The irritant pimelea factor P₅ (IIa) also with a tigliane skeleton and related to mancinellin (IIb), as wellas the irritant diterpene ester pimelea factor P₁ (IIa, simplexin) with daphnane skeleton, were found to be present in bothP. prostrata andP. simplex. Further the irritant homologue of simplexin, pimela factorIIIb was detected inP. prostrata. Some biogenetic consequences of these findings are discussed.Acknowledgment: The authors are deeply indebted to Dr T. Cashmore (Palmerton North, New Zealand) and Dr H. B. Roberts (Sydney, Australia) for kindly supplying plant materials.     

New tigliane and daphnane derivatives from Pimelea prostrata and Pimelea simplex

From the methanol extract of Pimelea prostrata, prostratin (I) and 2 autoxidation products have been isolated. They are tigliane derivatives and relatively nonirritant on the mouse ear. The irritant pimelea factor P5 (IIa) also with a tigliane skeleton and related to mancinellin (IIb), as well as the irritant diterpene ester pimelea factor P1 (IIa, simplexin) with daphnane skeleton, were found to be present in both P. prostrata and P. simplex. Further the irritant homologue of simplexin, pimela factor IIIb was detected in P. prostrata. Some biogenetic consequences of these findings are discussed.     

Effect of X-537A on the phosphorylated protein in sarcoplasmic reticulum vesicles

Summary The effect of the antibiotic X-537A on the phosphorylated ATPase (EP) was investigated. The results show that X-537A depresses the level of EP which is dependent on the Ca²⁺ gradient, while the Ca²⁺-independent EP is not affected. Acknowledgments. This work was supported by grants from the Instituto de Alta Cultura of the Portuguese Ministry of Education (No. CB/2) and the Calouste Gulbenkian Foundation.     

A SAXS-based ensemble model of the native and phosphorylated regulatory domain of the CFTR

The cystic fibrosis transmembrane conductance regulator (CFTR), the defective protein in cystic fibrosis, is an anion channel activated by protein kinase A phosphorylation. The regulatory domain (RD) of CFTR has multiple phosphorylation sites, and is responsible for channel activation. This domain is intrinsically disordered, rendering the structural analysis a difficult task, as high-resolution techniques are barely applicable. In this work, we obtained a biophysical characterization of the native and phosphorylated RD in solution by employing complementary structural methods. The native RD has a gyration radius of 3.25 nm, and a maximum molecular dimension of 11.4 nm, larger than expected for a globular protein of the same molecular mass. Phosphorylation causes compaction of the structure, yielding a significant reduction of the gyration radius, to 2.92 nm, and on the maximum molecular dimension to 10.2 nm. Using an ensemble optimization method, we were able to generate a low-resolution, three-dimensional model of the native and the phosphorylated RD based on small-angle X-ray scattering data. We have obtained the first experiment-based model of the CFTR regulatory domain, which will be useful to understand the molecular mechanisms of normal and pathological CFTR functioning.     

Fluorescence of indole derivatives

Zusammenfassung Die Verwendung von 1N Natronlauge und Essigsäureanhydrid bei der Bestimmung von Indolderivaten mit Hilfe der Fluoreszenzmethode erlaubt eine gute Differenzierung zwischen 5-Methoxyindolderivaten (z.B. Melatonin) und anderen Indolen. Versuche zur Verwendung der neuen Methode in biologischem Material, z.B. Epiphysenschnitten, sind im Gange.     

Effect of X-537A- on the phosphorylated protein in sarcoplasmic reticulum vesicles.

The effect of the antibiotic X537A on the phosphorylated ATPase (E approximately P) was investigated. The results show that X-537A depresses the level of E approximately P which is dependent on the Ca2+ gradient, while the Ca2+-independent E approximately P is not affected.     

Analysis of a sub-proteome which co-purifies with and is phosphorylated by the Golgi casein kinase

In an attempt to gain information about the identity of the Golgi apparatus casein kinase(s) (G-CK), responsible for the phosphorylation of caseins in lactating mammary gland, the proteins present in fractions enriched in G-CK activity eluted from DEAE-Sepharose and heparin-Sepharose columns were resolved by two-dimensional electrophoresis and analyzed by mass spectrometry. This led to the identification of 47 proteins altogether, none of which is a bona fide protein kinase. At least 9 of the identified proteins however, are readily phosphorylated by co-purifying G-CK activity, and 7 are physically associated with it to give supramolecular complex(es) of about 500 kDa as judged from Superdex S200 gel fitration and glycerol gradient ultracentrifugation experiments. In contrast, the apparent molecular weight of G-CK estimated from an in gel activity assay after SDSPAGE and renaturation is about 41 kDa. Many of the proteins phosphorylated by and/or associated with G-CK belong to the category of chaperonines, including HSP90, GRP-94 and −78, and various isoforms of protein disulfide isomerases, suggesting a global role of this kinase in the modulation of protein folding. Received 21 October 2005; received after revision 30 November 2005; accepted 6 December 2005 †These authors contributed equally to this work.