Publication Date:
1993-04-09
Description:
Electrostatic interactions in proteins are potentially quite strong, but these interactions are mitigated by the screening effects of water, ions, and nearby protein atoms. The early work of Kirkwood and Westheimer on small organic molecules showed that the extent of the screening may depend on whether charged or dipolar groups are involved. The dielectric and ionic screening of the interactions between the dipolar backbone amide groups of monomeric alpha helices and either (i) solvent-exposed charges or (ii) solvent-exposed dipoles at the amino terminus was measured. The dielectric screening effects are an order of magnitude greater for the backbone-charge interactions than for the backbone-dipole interactions, and the ionic strength dependence is substantially different in the two cases. These results suggest that interactions that involve the dipolar groups of proteins may be relatively more important for stability and function than is generally thought.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lockhart, D J -- Kim, P S -- New York, N.Y. -- Science. 1993 Apr 9;260(5105):198-202.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Massachusetts Institute of Technology, Cambridge Center 02142.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8469972" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Circular Dichroism
;
Electrochemistry
;
Hydrogen-Ion Concentration
;
Magnetic Resonance Spectroscopy
;
Molecular Sequence Data
;
Osmolar Concentration
;
Peptides/*chemistry
;
Protein Structure, Secondary
;
Thermodynamics
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
