共查询到3条相似文献,搜索用时 2 毫秒
1.
Shafqat J Melles E Sigmundsson K Johansson BL Ekberg K Alvelius G Henriksson M Johansson J Wahren J Jörnvall H 《Cellular and molecular life sciences : CMLS》2006,63(15):1805-1811
Using surface plasmon resonance (SPR) and electrospray mass spectrometry (ESI-MS), proinsulin C-peptide was found to influence
insulin-insulin interactions. In SPR with chip-bound insulin, C-peptide mixed with analyte insulin increased the binding,
while alone C-peptide did not. A control peptide with the same residues in random sequence had little effect. In ESI-MS, C-peptide
lowered the presence of insulin hexamer. The data suggest that C-peptide promotes insulin disaggregation. Insulin/insulin
oligomer μM dissociation constants were determined. Compatible with these findings, type 1 diabetic patients receiving insulin
and C-peptide developed 66% more stimulation of glucose metabolism than when given insulin alone. A role of C-peptide in promoting
insulin disaggregation may be important physiologically during exocytosis of pancreatic β-cell secretory granulae and pharmacologically
at insulin injection sites. It is compatible with the normal co-release of C-peptide and insulin and may contribute to the
beneficial effect of C-peptide and insulin replacement in type 1 diabetics.
Received 3 May 2006; received after revision 9 June 2006; accepted 12 June 2006 Free Online Access 相似文献
2.
The role of insulin and IGF-1 signaling in longevity 总被引:16,自引:0,他引:16
There are many theories of aging and parameters that influence lifespan, including genetic instability, telomerase activity and oxidative stress. The role of caloric restriction, metabolism and insulin and insulin-like growth factor-1 signaling in the process of aging is especially well conserved throughout evolution. These latter factors interact with each other, the former factors and histone deacetylases of the SIR family in a complex interaction to influence lifespan.Received 8 July 2004; received after revision 25 August 2004; accepted 17 September 2004 相似文献
3.
The polyamine putrescine might be formed via a degradation (catalyzed by spermidine/spermine N1-acetyltransferase, SSAT) of the higher polyamines spermidine and spermine to putrescine. The involvement of different intracellular signal pathways in the regulation of putrescine formation was studied in explants and in cultured cells of rat parotid glands by using receptor agonists that activate separate second messenger systems, and measuring their effects on the concentrations of putrescine, spermidine and spermine and on the SSAT activity. The -adrenoceptor agonist isoprenaline, which is an activator of cAMP formation, increased the putrescine concentration and stimulated the SSAT activity. Pilocarpine, a drug that activates the muscarinic receptors and thereby enhances the phosphoinositide turnover, had no effect on either the polyamine concentrations or on the SSAT activity. Epidermal growth factor (EGF), which induces activation of a protein tyrosine kinase, had no effect on the polyamine concentrations or on the SSAT activity. The adenylate cyclase activator forskolin increased the glandular levels of putrescine. Taken together, these findings suggest that increases in putrescine concentration in cultured rat parotid gland cells are accompanied by accumulation of cAMP. 相似文献