Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2004-6-11
pubmed:abstractText
Excessive activation of calpains (calcium-activated neutral proteases) is observed following spinal cord contusion injury, traumatic brain injury, stroke, and in neurodegenerative disorders including Alzheimer's disease. Calpain inhibition represents an attractive therapeutic target, but current calpain inhibitors possess relatively weak potency, poor specificity, and in many cases, limited cellular and blood-brain barrier permeability. We developed novel calpain inhibitors consisting of the endogenous inhibitor, calpastatin or its inhibitory domain I, fused to the protein transduction domain of the HIV trans-activator (Tat) protein (Tat(47-57)). The Tat-calpastatin fusion proteins were potent calpain inhibitors in a cell-free activity assay, but did not inhibit cellular calpain activity in primary rat cortical neurons when applied exogenously at concentrations up to 5 microM. The fusion proteins were able to transduce neurons, but were localized within endosome-like structures. A similar endosomal uptake was observed for Tat-GFP. Together, the results suggest that endosomal uptake of the Tat-calpastatin prevents its interaction with calpain in other cellular compartments. Endosomal uptake of proteins fused to the Tat protein transduction domain severely limits the applications of this methodology.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0014-4886
pubmed:author
pubmed:issnType
Print
pubmed:volume
188
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
161-70
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:15191812-Animals, pubmed-meshheading:15191812-Brain Diseases, pubmed-meshheading:15191812-Calcium-Binding Proteins, pubmed-meshheading:15191812-Calpain, pubmed-meshheading:15191812-Cell Compartmentation, pubmed-meshheading:15191812-Cells, Cultured, pubmed-meshheading:15191812-Cerebral Cortex, pubmed-meshheading:15191812-Dose-Response Relationship, Drug, pubmed-meshheading:15191812-Endosomes, pubmed-meshheading:15191812-Fetus, pubmed-meshheading:15191812-Gene Products, tat, pubmed-meshheading:15191812-Humans, pubmed-meshheading:15191812-Nerve Degeneration, pubmed-meshheading:15191812-Neurons, pubmed-meshheading:15191812-Protein Structure, Tertiary, pubmed-meshheading:15191812-Rats, pubmed-meshheading:15191812-Recombinant Fusion Proteins, pubmed-meshheading:15191812-Transduction, Genetic
pubmed:year
2004
pubmed:articleTitle
Tat-calpastatin fusion proteins transduce primary rat cortical neurons but do not inhibit cellular calpain activity.
pubmed:affiliation
Department of Anatomy and Neurobiology, and Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536-0230, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't