Linked Life Data

9448721

Source:http://linkedlifedata.com/resource/pubmed/id/9448721

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-2-18
pubmed:abstractText
The chimeric peptide galparan, composed of galanin (1-13) in the N-terminus and mastoparan in the C-terminus, was recently designed and synthesized. The effect of galparan on GTPase activity of rat brain cortical membranes was studied in comparison with the effect of mastoparan and galanin. GTPase was activated by mastoparan but it was noncompetitively inhibited by galparan, while no effect of galanin and galanin (1-13) was found in this tissue. EC50 of 12.1 +/- 2.1 microM and Hill coefficient of 2.1 +/- 0.6 was calculated for galparan from a dose-response curve and Ki of 19.1 +/- 0.3 microM was obtained by fitting the experimental data to the Michaelis-Menten equation valid in the presence of noncompetitive inhibitor. Mastoparan reversed the effect of galparan in a fully competitive manner while benzalkonium chloride did not prevent the inhibition of GTPase activity by galparan. Pertussis-toxin-catalyzed ribosylation of G proteins from rat brain cortical membranes resulted in 15% lower basal GTPase activity of our preparation but did not alter the parameters of the dose-response curve for galparan inhibition. The rate of GTP gamma S binding to G proteins from rat brain cortical membranes was not influenced by galparan. CD spectra revealed predominantly antiparallel beta-structure and unordered secondary structure of galparan in the buffer solution, while in the presence of lipid vesicles it adopted a higher amount of alpha-helix. Critical micelle concentration of galparan in buffer solution of 22 microM was determined. It is suggested that the reversal of GTPase activation by mastoparan to inhibition by galparan is due to different loci of action of these two peptides on G proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/GTP Phosphohydrolases, http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Galanin, http://linkedlifedata.com/resource/pubmed/chemical/Guanosine 5'-O-(3-Thiotriphosphate), http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Triphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Pertussis Toxin, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Virulence Factors, Bordetella, http://linkedlifedata.com/resource/pubmed/chemical/Wasp Venoms, http://linkedlifedata.com/resource/pubmed/chemical/galparan, http://linkedlifedata.com/resource/pubmed/chemical/mastoparan
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
349
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
321-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Differential regulation of GTPase activity by mastoparan and galparan.
pubmed:affiliation
Department of Neurochemistry and Neurotoxicology, Arrhenius Laboratories, Stockholm University, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't