Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1
| ISSN: |
1432-1424
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|---|---|
| Keywords: |
colicin E1 ; membrane channel ; chemical modification
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| Source: |
Springer Online Journal Archives 1860-2000
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| Topics: |
Biology
Chemistry and Pharmacology
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| Notes: |
Summary The two histidine residues of COOH-terminal channel-forming peptides of colicin E1 were modified by addition of a carbethoxy group through pretreatment with diethylpyrocarbonate. The consequences of the modification were examined by the action of the altered product on both phospholipid vesicles and planar membranes. At pH 6, where activity is low, histidine modification resulted in a decrease of the single channel conductance from 20 pS to approximately 9 pS and a decrease in the selectivity for sodium relative to chloride, showing that histidine modification affected the permeability properties of the channel. At pH 4, where activity is high, the single channel conductance and ion selectivity were not significantly altered by histidine modification. The histidine modification assayed at pH 4 resulted in a threefold increase in the rate of Cl− efflux from asolectin vesicles, and a similar increase in conductance assayed with planar membranes. This conductance increase was inferred to arise from an increase in the fraction of bound histidine-modified colicin molecules forming channels at pH 4, since the increase in activity was not due to (i) an increase in binding of the modified peptide, (ii) a change in ion selectivity, (iii) a change of single channel conductance, or (iv) a change in the pH dependence of binding. The sole cysteine in the colicin molecule was modified in 6m urea with 5,5′-dithiobis(2-nitrobenzoic acid). The activities of the colicin and its COOH-terminal tryptic peptide were found to be unaffected by cysteine modification, arguing against a role of (-SH) groups in protein insertion and/or channel formation.
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| Type of Medium: |
Electronic Resource
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| URL: |
| _version_ | 1798295679578144769 |
|---|---|
| autor | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. |
| autorsonst | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. |
| book_url | http://dx.doi.org/10.1007/BF01869392 |
| datenlieferant | nat_lic_papers |
| hauptsatz | hsatz_simple |
| identnr | NLM207075425 |
| issn | 1432-1424 |
| journal_name | The journal of membrane biology |
| materialart | 1 |
| notes | Summary The two histidine residues of COOH-terminal channel-forming peptides of colicin E1 were modified by addition of a carbethoxy group through pretreatment with diethylpyrocarbonate. The consequences of the modification were examined by the action of the altered product on both phospholipid vesicles and planar membranes. At pH 6, where activity is low, histidine modification resulted in a decrease of the single channel conductance from 20 pS to approximately 9 pS and a decrease in the selectivity for sodium relative to chloride, showing that histidine modification affected the permeability properties of the channel. At pH 4, where activity is high, the single channel conductance and ion selectivity were not significantly altered by histidine modification. The histidine modification assayed at pH 4 resulted in a threefold increase in the rate of Cl− efflux from asolectin vesicles, and a similar increase in conductance assayed with planar membranes. This conductance increase was inferred to arise from an increase in the fraction of bound histidine-modified colicin molecules forming channels at pH 4, since the increase in activity was not due to (i) an increase in binding of the modified peptide, (ii) a change in ion selectivity, (iii) a change of single channel conductance, or (iv) a change in the pH dependence of binding. The sole cysteine in the colicin molecule was modified in 6m urea with 5,5′-dithiobis(2-nitrobenzoic acid). The activities of the colicin and its COOH-terminal tryptic peptide were found to be unaffected by cysteine modification, arguing against a role of (-SH) groups in protein insertion and/or channel formation. |
| package_name | Springer |
| publikationsjahr_anzeige | 1986 |
| publikationsjahr_facette | 1986 |
| publikationsjahr_intervall | 8014:1985-1989 |
| publikationsjahr_sort | 1986 |
| publisher | Springer |
| reference | 92 (1986), S. 237-245 |
| schlagwort | colicin E1 membrane channel chemical modification |
| search_space | articles |
| shingle_author_1 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. |
| shingle_author_2 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. |
| shingle_author_3 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. |
| shingle_author_4 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. |
| shingle_catch_all_1 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 colicin E1 membrane channel chemical modification colicin E1 membrane channel chemical modification Summary The two histidine residues of COOH-terminal channel-forming peptides of colicin E1 were modified by addition of a carbethoxy group through pretreatment with diethylpyrocarbonate. The consequences of the modification were examined by the action of the altered product on both phospholipid vesicles and planar membranes. At pH 6, where activity is low, histidine modification resulted in a decrease of the single channel conductance from 20 pS to approximately 9 pS and a decrease in the selectivity for sodium relative to chloride, showing that histidine modification affected the permeability properties of the channel. At pH 4, where activity is high, the single channel conductance and ion selectivity were not significantly altered by histidine modification. The histidine modification assayed at pH 4 resulted in a threefold increase in the rate of Cl− efflux from asolectin vesicles, and a similar increase in conductance assayed with planar membranes. This conductance increase was inferred to arise from an increase in the fraction of bound histidine-modified colicin molecules forming channels at pH 4, since the increase in activity was not due to (i) an increase in binding of the modified peptide, (ii) a change in ion selectivity, (iii) a change of single channel conductance, or (iv) a change in the pH dependence of binding. The sole cysteine in the colicin molecule was modified in 6m urea with 5,5′-dithiobis(2-nitrobenzoic acid). The activities of the colicin and its COOH-terminal tryptic peptide were found to be unaffected by cysteine modification, arguing against a role of (-SH) groups in protein insertion and/or channel formation. 1432-1424 14321424 Springer |
| shingle_catch_all_2 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 colicin E1 membrane channel chemical modification colicin E1 membrane channel chemical modification Summary The two histidine residues of COOH-terminal channel-forming peptides of colicin E1 were modified by addition of a carbethoxy group through pretreatment with diethylpyrocarbonate. The consequences of the modification were examined by the action of the altered product on both phospholipid vesicles and planar membranes. At pH 6, where activity is low, histidine modification resulted in a decrease of the single channel conductance from 20 pS to approximately 9 pS and a decrease in the selectivity for sodium relative to chloride, showing that histidine modification affected the permeability properties of the channel. At pH 4, where activity is high, the single channel conductance and ion selectivity were not significantly altered by histidine modification. The histidine modification assayed at pH 4 resulted in a threefold increase in the rate of Cl− efflux from asolectin vesicles, and a similar increase in conductance assayed with planar membranes. This conductance increase was inferred to arise from an increase in the fraction of bound histidine-modified colicin molecules forming channels at pH 4, since the increase in activity was not due to (i) an increase in binding of the modified peptide, (ii) a change in ion selectivity, (iii) a change of single channel conductance, or (iv) a change in the pH dependence of binding. The sole cysteine in the colicin molecule was modified in 6m urea with 5,5′-dithiobis(2-nitrobenzoic acid). The activities of the colicin and its COOH-terminal tryptic peptide were found to be unaffected by cysteine modification, arguing against a role of (-SH) groups in protein insertion and/or channel formation. 1432-1424 14321424 Springer |
| shingle_catch_all_3 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 colicin E1 membrane channel chemical modification colicin E1 membrane channel chemical modification Summary The two histidine residues of COOH-terminal channel-forming peptides of colicin E1 were modified by addition of a carbethoxy group through pretreatment with diethylpyrocarbonate. The consequences of the modification were examined by the action of the altered product on both phospholipid vesicles and planar membranes. At pH 6, where activity is low, histidine modification resulted in a decrease of the single channel conductance from 20 pS to approximately 9 pS and a decrease in the selectivity for sodium relative to chloride, showing that histidine modification affected the permeability properties of the channel. At pH 4, where activity is high, the single channel conductance and ion selectivity were not significantly altered by histidine modification. The histidine modification assayed at pH 4 resulted in a threefold increase in the rate of Cl− efflux from asolectin vesicles, and a similar increase in conductance assayed with planar membranes. This conductance increase was inferred to arise from an increase in the fraction of bound histidine-modified colicin molecules forming channels at pH 4, since the increase in activity was not due to (i) an increase in binding of the modified peptide, (ii) a change in ion selectivity, (iii) a change of single channel conductance, or (iv) a change in the pH dependence of binding. The sole cysteine in the colicin molecule was modified in 6m urea with 5,5′-dithiobis(2-nitrobenzoic acid). The activities of the colicin and its COOH-terminal tryptic peptide were found to be unaffected by cysteine modification, arguing against a role of (-SH) groups in protein insertion and/or channel formation. 1432-1424 14321424 Springer |
| shingle_catch_all_4 | Bishop, L. J. Cohen, F. S. Davidson, V. L. Cramer, W. A. Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 colicin E1 membrane channel chemical modification colicin E1 membrane channel chemical modification Summary The two histidine residues of COOH-terminal channel-forming peptides of colicin E1 were modified by addition of a carbethoxy group through pretreatment with diethylpyrocarbonate. The consequences of the modification were examined by the action of the altered product on both phospholipid vesicles and planar membranes. At pH 6, where activity is low, histidine modification resulted in a decrease of the single channel conductance from 20 pS to approximately 9 pS and a decrease in the selectivity for sodium relative to chloride, showing that histidine modification affected the permeability properties of the channel. At pH 4, where activity is high, the single channel conductance and ion selectivity were not significantly altered by histidine modification. The histidine modification assayed at pH 4 resulted in a threefold increase in the rate of Cl− efflux from asolectin vesicles, and a similar increase in conductance assayed with planar membranes. This conductance increase was inferred to arise from an increase in the fraction of bound histidine-modified colicin molecules forming channels at pH 4, since the increase in activity was not due to (i) an increase in binding of the modified peptide, (ii) a change in ion selectivity, (iii) a change of single channel conductance, or (iv) a change in the pH dependence of binding. The sole cysteine in the colicin molecule was modified in 6m urea with 5,5′-dithiobis(2-nitrobenzoic acid). The activities of the colicin and its COOH-terminal tryptic peptide were found to be unaffected by cysteine modification, arguing against a role of (-SH) groups in protein insertion and/or channel formation. 1432-1424 14321424 Springer |
| shingle_title_1 | Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 |
| shingle_title_2 | Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 |
| shingle_title_3 | Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 |
| shingle_title_4 | Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 |
| sigel_instance_filter | dkfz geomar wilbert ipn albert fhp |
| source_archive | Springer Online Journal Archives 1860-2000 |
| timestamp | 2024-05-06T09:40:02.623Z |
| titel | Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 |
| titel_suche | Chemical modification of the two histidine and single cysteine residues in the channel-forming domain of colicin E1 |
| topic | W V |
| uid | nat_lic_papers_NLM207075425 |