Salt bridges: Difference between revisions
Jump to navigation
Jump to search
Eric Martz (talk | contribs) No edit summary |
Eric Martz (talk | contribs) No edit summary |
||
| Line 8: | Line 8: | ||
A salt bridge is generally considered to exist when the centers of charge are 4 Å or less apart<ref>Jeffrey, George A., An introduction to hydrogen bonding, Oxford University Press, 1997. Page 192.</ref>. The center of charge of the arginine sidechain is the zeta carbon<ref name='GD'>PMID: 10449714</ref>. The energetic significance of such complementary charge pairs is a complex function of the local environment. | A salt bridge is generally considered to exist when the centers of charge are 4 Å or less apart<ref>Jeffrey, George A., An introduction to hydrogen bonding, Oxford University Press, 1997. Page 192.</ref>. The center of charge of the arginine sidechain is the zeta carbon<ref name='GD'>PMID: 10449714</ref>. The energetic significance of such complementary charge pairs is a complex function of the local environment. | ||
Proteins from [[extremophiles|thermophiles]] have more salt bridges than do proteins from mesophiles<ref>PMID: 11793224</ref><ref>PMID: 11577980</ref>. These additional salt bridges contribute to stability, resisting denaturation by high temperature<ref>PMID: 21720566</ref><ref>PMID: 31360001</ref>. | Proteins from [[extremophiles|thermophiles]] have more salt bridges than do proteins from mesophiles<ref>PMID: 11793224</ref><ref name="kumar">PMID: 11577980</ref>. These additional salt bridges contribute to stability, resisting denaturation by high temperature<ref>PMID: 21720566</ref><ref>PMID: 31360001</ref>. | ||
==Examples== | ==Examples== | ||
===Thermophile vs. mesophile=== | ===Thermophile vs. mesophile=== | ||
Glutamate dehydrogenase structures have been determined at about 2 Å resolution for both a thermophile, ''Pyrococcus furiosus'' ([[1gtm]]), and a mesophile, ''Clostridium symbiosum'' ([[1hrd]]). The thermophile's protein has 1.7 fold more N and O atoms engaged in salt bridges than does the protein from the mesophile (301 vs. 175 respectively, as counted by [[FirstGlance]]. | Glutamate dehydrogenase structures have been determined at about 2 Å resolution for both a thermophile, ''Pyrococcus furiosus'' ([[1gtm]]), and a mesophile, ''Clostridium symbiosum'' ([[1hrd]])<ref name="kumar" />. The thermophile's protein has 1.7 fold more N and O atoms engaged in salt bridges than does the protein from the mesophile (301 vs. 175 respectively, as counted by [[FirstGlance]]. | ||
===Ultraviolet-B receptor=== | ===Ultraviolet-B receptor=== | ||