Linked Life Data

1254592

Source:http://linkedlifedata.com/resource/pubmed/id/1254592

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1976-6-2
pubmed:abstractText
Circular dichroism and difference ultraviolet visible spectra were obtained for cobalt hemoglobin derivatives. At 287 nm the ellipticity difference between the oxy- and deoxycobaltohemoglobin is about one-half as great as that for the native proteins indicating smaller quaternary conformational changes for the former. Deoxygenation increases the Soret rotational strengths of both iron and cobalt hemoglobins to comparable degrees suggesting similar conformational changes for their aromatic residues near the "heme." Deoxygenation causes a much larger decrease of L band ellipticity for iron than cobalt hemoglobin. Circular dichroism spectra of nitrosylcobaltohemoglobin indicate the molecule to have a T quaternary structure. The circular dichroism spectra of cobaltihemoglobin do not seem to fit the patterns of the other cobalt derivatives and its 287 nm ellipticity is pH-dependent. From the shape of the Soret circular dichroism spectra, it is estimated that the transition dipole makes an angle with the line joining the two opposing pyrrole nitrogens of about 60 degrees for oxy- and deoxycobaltohemoglobin, 80 degrees for cobaltihemoglobin, as compared to 70 degrees for the native oxy- and deoxyhemoglobins. Inositol hexaphosphate has little or no effect on the circular dichroism spectra of cobalt hemoglobins in the 287 nm region, but it significantly increases the Soret rotational strength and decreases the L band ellipticity. The results are interpreted to mean that polyphosphates modify primarily the protein structure of hemoglobins at the tertiary level, and that the intersubunit interactions are weak in cobalt hemoglobins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
251
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1670-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Allosteric transitions in cobalt hemoglobins.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.