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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn Apr 2015

Nonenzymatic Glycosylation Of Erythrocyte Membrane Proteins. Relevance To Diabetes, J A. Miller, Ellen M. Gravallese, H F. Bunn

Ellen M. Gravallese

Nonenzymatic glycosylation of proteins of the erythrocyte membrane was determined by incubating erythrocyte ghosts with [3H]borohydride. The incorporation of tritium into protein provides a reliable assay of ketoamine linkages. The membrane proteins from 18 patients with diabetes incorporated twice as much radioactivity as membrane proteins from normal erythrocytes. After acid hydrolysis, amino acid analysis showed that the majority of radioactivity was localized to glucosyllysine. Autoradiograms showed that all of the major proteins of the erythrocyte membrane, separated by electrophoresis on sodium dodecyl sulfate gels, contained ketoamine linkages. No protein bands in either normal or diabetic erythrocytes showed significant preferential labeling. …


Identification Of Disufide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1, Morgan E. Roberts, Jacquelyn P. Crail, Megan M. Laffoon, William G. Fernandez, Michael A. Menze, Mary E. Konkle Dec 2013

Identification Of Disufide Bond Formation Between Mitoneet And Glutamate Dehydrogenase 1, Morgan E. Roberts, Jacquelyn P. Crail, Megan M. Laffoon, William G. Fernandez, Michael A. Menze, Mary E. Konkle

Michael Menze

MitoNEET is a protein that was identified as a drug target for diabetes, but its cellular function as well as its role in diabetes remains elusive. Protein pull-down experiments identified glutamate dehydrogenase 1 (GDH1) as a potential binding partner. GDH1 is a key metabolic enzyme with emerging roles in insulin regulation. MitoNEET forms a covalent complex with GDH1 through disulfide bond formation and acts as an activator. Proteomic analysis identified the specific cysteine residues that participate in the disulfide bond. This is the first report that effectively links mitoNEET to activation of the insulin regulator GDH1.


Diabetic Rates And Mice Are Resistent To Porcine And Human Insulin: Flawed Experimental Models For Testing Islet Xenograft, A. Pepper, C. Gall, D. Mazzuca, C.W.J. Melling, D. White Dec 2008

Diabetic Rates And Mice Are Resistent To Porcine And Human Insulin: Flawed Experimental Models For Testing Islet Xenograft, A. Pepper, C. Gall, D. Mazzuca, C.W.J. Melling, D. White

Jamie Melling

BACKGROUND: Islet transplantation is potentially a promising therapy for the restoration of carbohydrate control to diabetic patients. However, the global application of islet transplantation requires a ubiquitous source of beta cells. The xenotransplantation of porcine islets would provide such a source. Success in porcine islet xenografting has been achieved in diabetic primates. However, there are few reports of reversal of diabetes with porcine islet xenografts in rodent models of diabetes, relative to the number of successful rodent experiments performed as allografts. Here we report for the first time the inability of porcine (and human) insulin to control blood glucose levels …


Imaging Of Transplanted Pancreatic Islets In Vivo, P. Joo Ho Tai, C. Foster, C. Hasil, C.W.J. Melling, D. White Dec 2007

Imaging Of Transplanted Pancreatic Islets In Vivo, P. Joo Ho Tai, C. Foster, C. Hasil, C.W.J. Melling, D. White

Jamie Melling

No abstract provided.


Imaging Islets Labeled Wth Magnetic Nanoparticules At 1.5 Tesla, J.H. Tai, Paula Foster, Alma Rosales, Biao Feng, Craig Ha, Violetta Martinez, Soha Ramadan, Jonatan Snir, C.W. Melling, Savita Dhanvantari, Brian Rutt, David White Dec 2005

Imaging Islets Labeled Wth Magnetic Nanoparticules At 1.5 Tesla, J.H. Tai, Paula Foster, Alma Rosales, Biao Feng, Craig Ha, Violetta Martinez, Soha Ramadan, Jonatan Snir, C.W. Melling, Savita Dhanvantari, Brian Rutt, David White

Jamie Melling

We have developed a magnetic resonance imaging (MRI) technique for imaging Feridex (superparamagnetic iron oxide [SPIO])-labeled islets of Langerhans using a standard clinical 1.5-Tesla (T) scanner and employing steady-state acquisition imaging sequence (3DFIESTA). Both porcine and rat islets were labeled with SPIO by a transfection technique using a combination of poly-l-lysine and electroporation. Electron microscopy demonstrated presence of SPIO particles within the individual islet cells, including beta-cells and particles trapped between cell membranes. Our labeling method produced a transfection rate of 860 pg to 3.4 ng iron per islet, dependent on the size of the islet. The labeling procedure did …