首页 | 本学科首页   官方微博 | 高级检索  
   检索      


The propeptide Asn1-Tyr126 is the storage form of rat atrial natriuretic factor.
Authors:G Thibault  R Garcia  J Gutkowska  J Bilodeau  C Lazure  N G Seidah  M Chrétien  J Genest  and M Cantin
Abstract:Granules from rat atria were isolated by differential centrifugation and by a 53% (v/v) Percoll gradient after tissue homogenization in 0.25 M-sucrose/50 mM-Na2EDTA. About 40% of the immunoreactive ANF (atrial natriuretic factor) sedimented with the atrial granules during differential centrifugations. On the Percoll gradient, two distinct bands were observed. Cell debris, mitochondria, lysosomes, myofilaments and microsomes were mostly contained in the lightest-density (rho) (1.03-1.07 g/ml) fraction, as demonstrated by electron microscopy and by enzymic markers such as lactate dehydrogenase, monoamine oxidase, cytochrome c reductase, beta-glucuronidase and acid phosphatase. Atrial granules were mostly contained in the denser (rho 1.11-1.15 g/ml) band and were only slightly contaminated by lysosomes, as shown by beta-glucuronidase activity. Analysis of the ANF content in these isolated granules by h.p.l.c., amino acid composition and sequencing demonstrated that it was only the pro-ANF ANF-(Asn1-Tyr126)-peptide]. The precursor was present in all granules, as demonstrated by immunocytochemistry. Since hormonal propeptides usually undergo intracellular processing, and the matured peptides are subsequently stored in the secretory granules, these results indicate that the processing pathway of ANF may be different from that of other hormonal peptides.
Keywords:
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号