Adlyfe Study on the Detection of Misfolded Proteins Published in the Journal Transfusion



Misfolded Protein Diagnostic (MPD) Shown to be Sensitive and Specific
Technology Applicable for the Detection of a Host of Amyloid Neurological
Diseases including Creutzfeldt-Jakob Disease (CJD), Alzheimer's, and
Parkinson Disease

ROCKVILLE, Md., Aug. 29 /PRNewswire/ -- Adlyfe, a private company
developing novel diagnostic testing technologies for early targets of
amyloid diseases, announced today the publication of a study, "Detection of
misfolded prion protein in blood with conformationally sensitive peptides,"
in the August 2007 issue of the journal Transfusion. The monthly
publication is the official peer-reviewed journal of the AABB, formerly
known as the American Association of Blood Banks.
The published study examined the ability of Adlyfe's Misfolded Protein
Diagnostic (MPD) to detect the presence of misfolded proteins in brain,
serum and plasma. Study results demonstrated that Adlyfe's MPD assay is a
sensitive and specific test for the detection misfolded prion proteins that
may be useful in both preclinical and clinical diagnosis transmissible
spongiform encephalopathy (TSE) diseases in both animals and humans.
Scientists have tried to develop a preclinical diagnostic test for TSE
since the discovery that humans with variant Creutzfeldt-Jakob disease can
transmit disease via blood transfusions, though there are several
challenges to detecting misfolded proteins in the blood. The coexistence of
a large amount of the protein in its normally folded shape and the fact
that misfolded proteins do not trigger an immune system response that would
enable diagnosis based on the detection of antibodies. In addition, most
standard detection methods are not sensitive enough to detect the low level
of misfolded proteins in the blood, especially during early disease stages.
These challenges have largely restricted diagnostic tests for amyloid
diseases to the use of postmortem tissue.
Adlyfe's novel technology is based on the synthesis of conformationally
sensitive peptides (chains of amino acids that are smaller than proteins)
which are created to target specific protein shapes associated with various
diseases. The interaction of the target protein with Adlyfe's proprietary
peptides produces a conformational change that transduces a fluorescent
signal. Further amplification of the signal is generated as additional
ligands undergo conformational changes. This is the basis for the tests'
sensitivity and ability to detect very low amyloid protein levels before
symptoms occur.
"The publication of this study validates the utility and sensitivity of
our MPD assay in detecting misfolded proteins in TSE, even at low levels,"
said Chief Executive Officer Alan S. Rudolph, Ph.D. "We believe our test
meets the dual diagnostic demands of confirmatory testing in symptomatic
subjects suspected of having the disease and as a screening test to
identify infection in its earliest phases. Our unique diagnostic approach
and technology is applicable to a number of neurological diseases
associated with protein buildup in tissues such as Creutzfeldt-Jakob
disease (CJD), Alzheimer's, and Parkinson Disease."
About Adlyfe
Adlyfe Inc. was established early in 2003 to develop novel technologies
for blood testing for early targets of amyloid diseases. Adlyfe is
developing a novel test for the detection and amplification of amyloid
proteins as early biomarkers of fatal brain and amyloid diseases such as
Alzheimer's disease, Parkinson's disease, Creutzfeldt-Jacob disease,
Huntington's disease, systemic amyloidosis, diabetes and other diseases.
The Company's novel technology is based on the synthesis of small
peptide, or Pronucleon(TM) ligands, that are amino acid sequence matched to
target amyloids of interest. Ligand sequences are selected based on regions
of the target protein known to undergo conformational changes (structural
changes in shape) associated with amyloid aggregation (and eventual amyloid
plaque formation). These aggregates are associated with disease state
progression in a number of brain-wasting and amyloid diseases.
Adlyfe, a privately-held corporation, was initially funded by the
Defense Advanced Research Projects Agency (DARPA), the U.S. Army Medical
Research and Materiel Command, the National Heart, Lung and Blood
Institute, and Britain's Department for Environment, Food and Rural
Affairs. More recently, Adlyfe raised additional funding with venture
capital firms Canaan Venture Partners and Burrill Associates.
Internet Website: http://www.adlyfe.com

For More Information
Media:
Janine McCargo
1-646-536-7033
jmccargo@theruthgroup.com

The dopamine transporter proteome
Torres GE.

Dopamine (DA) uptake through the neuronal plasma membrane DA transporter (DAT) is essential for the maintenance of normal DA homeostasis in the brain. The DAT-mediated re-uptake system limits not only the intensity but also the duration of DA actions at presynaptic and postsynaptic receptors. This protein is the primary target for cocaine and amphetamine, both highly addictive and major substances of abuse worldwide. DAT is also the molecular target for therapeutic agents used in the treatment of mental disorders, such as attention deficit hyperactivity disorder and depression. Given the role played by the DAT in regulation of DA neurotransmission and its contribution to the abuse potential of psychostimulants, it becomes not only important but also necessary to understand the functional regulation of this protein. To investigate the cellular and molecular mechanisms associated with DAT function and regulation, our laboratory and others have embarked on a systematic search for DAT protein-protein interactions. Recently, a growing number of proteins have been shown to interact with DAT. These novel interactions might be important in the assembly, targeting, trafficking and/or regulation of transporter function. In this review, I summarize the main findings obtained from the characterization of DAT-interacting proteins and discuss the functional implications of these novel interactions. Based on these new data, I propose to use the term DAT proteome to explain how interacting proteins regulate DAT function. These novel interactions might help define new mechanisms associated with the function of the transporter.

The identification of DAT-interacting proteins is rapidly facilitating the characterization of cellular processes that regulate the synthesis, assembly, targeting, trafficking and functional properties of the transporter. The proteins identified so far probably represent the 'tip of the iceberg' in terms of the entire complement of proteins that interact with this transporter. A major goal in future years will be to identify all proteins that directly or indirectly form part of the DAT proteome. New methods, such as mass spectrometry coupled with better purification techniques, should be employed in this effort. Once these proteins are identified, we will need to understand the temporal and spatial distribution of these interactions. Some proteins will be required for transporter synthesis and assembly, some for targeting to distinct subcellular microdomains, and some for trafficking and recycling. It is also conceivable that unexpected functions associated with the transporter will be discovered through the identification of novel protein-protein interactions. Disruption of specific protein-protein interactions with competition peptides, mutants lacking binding sites or small interfering RNA-mediated suppression of interacting proteins will be crucial for examining the physiological significance of these novel interactions.

Finally, given the role of the DAT in the regulation of DA homeostasis, it will be important to investigate to what extent disruption of these novel protein-protein interactions is associated with dysfunction of the DA system. These novel interacting proteins might represent important new targets for the treatment of mental diseases.

[J Neurochem. 2006] - open access
Volume 97 Page 3 - April 2006

Defining the dopamine transporter proteome by convergent biochemical and in silico analyses
Maiya R, Ponomarev I, Linse KD, Harris RA, Mayfield RD.; Institute for Cellular and Molecular Biology, Waggoner Center for Alcohol and Addiction Research and Section of Neurobiology, University of Texas at Austin, Austin, TX, USA.

Monoamine transporters play a key role in neuronal signaling by mediating reuptake of neurotransmitters from the synapse. The function of the dopamine transporter (DAT), an important member of this family of transporters, is regulated by multiple signaling mechanisms, which result in altered cell surface trafficking of DAT. Protein-protein interactions are likely critical for this mode of transporter regulation. In this study, we identified proteins associated with DAT by immunoprecipitation (IP) followed by mass spectrometry. We identified 20 proteins with diverse cellular functions that can be classified as trafficking proteins, cytoskeletal proteins, ion channels and extracellular matrix-associated proteins. DAT was found to associate with the voltage-gated potassium channel Kv2.1 and synapsin Ib, a protein involved in regulating neurotransmitter release. An in silico analysis provided evidence for common transcriptional regulation of the DAT proteome genes. In summary, this study identified a network of proteins that are primary candidates for functional regulation of the DAT, an important player in mechanisms of mental disorders and drug addiction.