Linked Life Data

7739051

Source:http://linkedlifedata.com/resource/pubmed/id/7739051

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-6-5
pubmed:abstractText
The three-dimensional (3D) reconstructions of the di-decameric forms of alpha D and beta C-hemocyanins of the Roman snail Helix pomatia and of the decameric half molecules of alpha D-hemocyanin were carried out on frozen-hydrated specimens observed in the electron microscope by using the random conical tilt series method. The three 3D volumes were examined by computing solid-body surface representations and slices through the volume and by eroding the structure progressively through raising of the threshold. The di-decameric molecule of alpha D and beta C-hemocyanins, reconstructed from side views, are very similar and are composed of a cylindrical wall, comprising ten oblique wall units, and of two collar complexes located at both ends of the cylinder, comprising each five arches and an annular collar made up of five collar units. Erosion of the structure reveals that the wall looks like a segment of a five-stranded right-handed helix and that each oblique wall unit resembles a figure 8 inclined to the right. The decameric half molecule of alpha D-hemocyanin, reconstructed from end-on views, resembles the whole molecule, except that the collar is thinner and appears composed of five independent collar complex units. It is suggested that the difference in structural appearance of the collar complex between the whole and the half alpha D-hemocyanin may be due to the missing cone artifact, induced by the angular limitations imposed by the goniometer of the electron microscope. The comparison between the alpha D-hemocyanin and the beta C-di-decameric hemocyanin at high thresholds suggests that in the beta C-hemocyanin the oblique wall units of each half molecule may be linked by two connections, whereas in alpha D-hemocyanin there may be only one. This difference in the number of connections may be responsible for the lower stability of the alpha D molecule at high salt concentration.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
248
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
431-48
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Three-dimensional reconstruction of the alpha D and beta C-hemocyanins of Helix pomatia from frozen-hydrated specimens.
pubmed:affiliation
Laboratoire de Biochimie Fondamentale CNRS, Tours, France.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't