Linked Life Data

10669784

Source:http://linkedlifedata.com/resource/pubmed/id/10669784

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-6-22
pubmed:abstractText
Arginase I is a homotrimeric protein with a binuclear manganese cluster. At the C-terminus of each monomer, the polypeptide chain forms an unusual S-shaped oligomerization motif where the majority of intermonomer contacts are located [Z.F. Kanyo, L.R. Scolnick, D.E. Ash, D.W. Christianson, Nature 383 (1996) 554-557]. In order to study the implication of this motif in the quaternary structure of human arginase I, we have constructed a truncated arginase lacking the 14 C-terminal amino acids, leaving Arg-308 as the last residue in the sequence. The resulting protein retains its trimeric structure, as determined by gel filtration (molecular mass 94 kDa). The same result was obtained in the presence of high ionic strength (KCl 0.5 M). Both data indicate that neither the S-shaped motif nor Arg-308 are fundamental in keeping the trimeric quaternary structure. Data obtained from intrinsic anisotropy and fluorescence intensity studies allow us to predict that the distance between the two unique tryptophans in the sequence is 2.9 nm in the native arginase and 4.1 nm for the truncated mutant. These distances allow us to assume a different conformational state in the truncated arginase without any change in its quaternary structure, suggesting that the carboxy-terminal motif is not the most prominent domain implicated in the quaternary structure of human arginase. Collisional quenching studies reinforce this possibility, since using I(-) as quenching molecule we were able to distinguish the two tryptophans in the truncated arginase. Moreover, kinetic studies show that the truncated mutant was fully active. In summary, the main conclusion about the structure of the human arginase I, derived from our study, is that the C-terminal S-shaped motif is not basic to the maintenance of the quaternary structure nor to the activity of the protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
1476
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
181-90
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Implications of the S-shaped domain in the quaternary structure of human arginase.
pubmed:affiliation
Departamento de Bioquímica y Biología Molecular, Facultad de Veterinaria, Universidad de Extremadura, Av. Universidad s/n, 10071, Cáceres, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't