Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-5-8
pubmed:abstractText
A monomeric version of triosephosphate isomerase from Trypanosoma brucei, MonoTIM, has very low activity, and the same is true for all of the additional monomeric variants so far constructed. Here, we subjected MonoTIM to directed evolution schemes to achieve an activity improvement. The construction of a suitable strain for genetic selection provided an effective way to obtain active catalysts from a diverse population of protein variants. We used this tool to identify active mutants from two different strategies of mutagenesis: random mutagenesis of the whole gene and randomization of loop 2. Both strategies converged in the isolation of mutations Ala43 to Pro and Thr44 to either Ala or Ser, when randomizing the entire gene or to Arg in the case of randomization of loop 2. The kinetic characterization of the two more active mutants showed an increase of 11-fold in k(cat) and a reduction of 4-fold in K(m) for both of them, demonstrating the sensitivity of the selection method. A small difference in growth rate is observed when both mutant genes are compared, which seems to be attributable to a difference in solubility of the expressed proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0269-2139
pubmed:author
pubmed:issnType
Print
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
149-55
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:11342710-Amino Acid Sequence, pubmed-meshheading:11342710-Amino Acid Substitution, pubmed-meshheading:11342710-Amino Acids, pubmed-meshheading:11342710-Animals, pubmed-meshheading:11342710-Binding Sites, pubmed-meshheading:11342710-Catalysis, pubmed-meshheading:11342710-DNA Ligases, pubmed-meshheading:11342710-Directed Molecular Evolution, pubmed-meshheading:11342710-Enzyme Activation, pubmed-meshheading:11342710-Escherichia coli, pubmed-meshheading:11342710-Gene Library, pubmed-meshheading:11342710-Genetic Variation, pubmed-meshheading:11342710-Growth, pubmed-meshheading:11342710-Kinetics, pubmed-meshheading:11342710-Models, Molecular, pubmed-meshheading:11342710-Molecular Structure, pubmed-meshheading:11342710-Mutagenesis, Insertional, pubmed-meshheading:11342710-Mutagenesis, Site-Directed, pubmed-meshheading:11342710-Oligonucleotides, pubmed-meshheading:11342710-Polymerase Chain Reaction, pubmed-meshheading:11342710-Protein Engineering, pubmed-meshheading:11342710-Sequence Alignment, pubmed-meshheading:11342710-Sequence Analysis, DNA, pubmed-meshheading:11342710-Structure-Activity Relationship, pubmed-meshheading:11342710-Thermodynamics, pubmed-meshheading:11342710-Triose-Phosphate Isomerase, pubmed-meshheading:11342710-Trypanosoma brucei brucei
pubmed:year
2001
pubmed:articleTitle
Different strategies to recover the activity of monomeric triosephosphate isomerase by directed evolution.
pubmed:affiliation
Instituto de Biotecnología, UNAM, Apartado Postal 510-3, Cuernavaca, Morelos, 62271, México.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't