排序方式: 共有22条查询结果,搜索用时 15 毫秒
1.
MONIQUE DAVRIL MIREILLE GUAY KIA-KI HAN FRANCOIS LAMY 《Chemical biology & drug design》1987,29(1):68-77
This report describes the use of photolysis and ozonolysis as a means of achieving complete cleavage of the pyridinium ring of (iso)desmosine in crosslinked elastin peptides. Although photolysis leads to the opening of the ring with concomitant formation of lysine, the peptide chains remain attached. Subsequent ozonolysis is able to completely achieve the cleavage of the rest of the ring skeleton, thus leading to the separation of the peptide chains. Formation of new amino acids, i.e. α-aminoadipic and glutamic acids, is emphasized. Localization of these amino acids within the released peptides should be of help in structural investigations on the crosslinking zones involving either isodesmosine or desmosine. However, other amino acids such as tyrosine and phenylalanine are sensitive to this procedure and side reactions occur which are responsible for peptide bond cleavage with the formation of breakdown products. 相似文献
2.
ANDRÉ PISAPIA JEAN YVES LEHEUZEY JACQUES FAURE BERNARD SIMONETTI LASZLO SZATMARY MIREILLE CARTA ROGER ROSARIO CLAUDE BARNAY GUY DUPORT 《Pacing and clinical electrophysiology : PACE》1988,11(1):23-24
The electrophysiologic mechanisms of sinus dysfunction have recently been determined by direct recordings of the sinus node electrogram. The association of various degrees of abnormalities in the formation of the impulse within the sinus node and of sinoatrial conduction block, represents the pathophysiological substrate of the mechanism of sinus node dysfunction. The purpose of this work is to present clinical and experimental data supporting the concept of sinus node isolation. In our clinical case, the sinus node was probably intact despite aspects of sinus node dysfunction on the surface ECG. Sinus node electrograms were recorded with a sinoatrial conduction time of 100 ms (normal values in our laboratory: 83 ms +/- 38 ms). Atrial mapping demonstrated that the area depolarized by the sinus node involved a 2 cm2 zone surrounding it. This perisinusal activity could not be recorded on the surface ECG. Both exit and entry blocks in the sinus node were demonstrated. Our experimental data showed a total desynchronization between the electrical activity of the sinus node and that of the atrium under hypoxic conditions. Both types of cases demonstrated that an atrial dysrhythmia was coexisting with regular sinus activity. From these data we concluded that a sinus node free from any pathological involvement could be associated with severe symptoms of sinus node dysfunction on the surface ECG. 相似文献
3.
4.
5.
6.
7.
8.
MIREILLE YVON CLAIRE CHABANET JEAN-PIERRE PLISSIER 《Chemical biology & drug design》1989,34(3):166-176
The assessment of proteolysis levels is often achieved by global quantification of the peptides soluble at different TCA concentrations, but little information is available on the features of this precipitation mechanism. Peptic, tryptic and chymotryptic digests of xsl, β, and κ caseins have been prepared and fractionated by RP-HPLC and each isolated peptide was identified. Each digest was precipitated by adding TCA to different final concentrations (2, 4, 8, and 12%). The soluble fraction was analysed by RP-HPLC. Relationships have been searched between the properties of 75 peptides obtained in this way, and their solubilities in TCA. The best correlation was found with the peptide retention time in RP-HPLC, which can be regarded as the experimental measure of peptide hydrophobicity. We concluded that TCA, by interacting with peptides, induces an increase of the hydrophobicity of peptides which can lead to aggregation through hydrophobic interactions. 相似文献
9.
10.