Josip Blonder

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Steroid hormones are critical for organismal development and health. The rate-limiting step in steroidogenesis is the transport of cholesterol from the outer mitochondrial membrane (OMM) to the cytochrome P450 enzyme CYP11A1 in the inner mitochondrial membrane (IMM). Cholesterol transfer occurs through a complex termed the "transduceosome," in which(More)
The prostate-specific homeodomain protein NKX3.1 is a tumor suppressor that is commonly down-regulated in human prostate cancer. Using an NKX3.1 affinity column, we isolated topoisomerase I (Topo I) from a PC-3 prostate cancer cell extract. Topo I is a class 1B DNA-resolving enzyme that is ubiquitously expressed in higher organisms and many prokaryotes.(More)
Adoption of targeted mass spectrometry (MS) approaches such as multiple reaction monitoring (MRM) to study biological and biomedical questions is well underway in the proteomics community. Successful application depends on the ability to generate reliable assays that uniquely and confidently identify target peptides in a sample. Unfortunately, there is a(More)
Multiple endocrine neoplasia syndrome IIB is an inherited autosomal dominant disorder with variable penetrance. Multiple organ systems are involved with a characteristic triad of medullary thyroid carcinoma, pheochromocytoma, and alimentary tract ganglioneuromas. Most patients have characteristic facies with patulous lips and thickened tarsal plates of the(More)
An increasing number of proteomic strategies rely on liquid chromatography-tandem mass spectrometry (LC-MS/MS) to detect and identify constituent peptides of enzymatically digested proteins obtained from various organisms and cell types. However, sample preparation methods for isolating membrane proteins typically involve the use of detergents and(More)
OBJECTIVE To ascertain the influence of estrogen replacement therapy (ERT) on blood and urinary zinc in postmenopausal women. METHODS Thirty-seven postmenopausal women aged 53.2 +/- 3.7 years were examined. All were treated with conjugated estrogens 0.625 mg and medroxyprogesterone acetate 5 mg. Zinc, magnesium, calcium, phosphate, and alkaline(More)
In this study, a multidimensional fractionation approach was combined with MS/MS to increase the capability of characterizing complex protein profiles of mammalian neuronal cells. Proteins extracted from primary cultures of cortical neurons were digested with trypsin followed by fractionation using strong cation exchange chromatography. Each of these(More)
The core prerequisites for an efficient proteome-scale analysis of mammalian membrane proteins are effective isolation, solubilization, digestion and multidimensional liquid chromatography-tandem mass spectrometry (LC-MS/MS). This protocol is for analysis of the mammalian membrane proteome that relies on solubilization and tryptic digestion of membrane(More)
The endothelium plays a critical role in orchestrating the inflammatory response seen during sepsis. Many of the inflammatory effects of Gram-negative sepsis are elicited by lipopolysaccharide (LPS), a glycolipid component of bacterial cell walls. Lipid-rich microdomains have been shown to concentrate components of the LPS signaling system. However, much(More)
A simple and rapid method for characterizing hydrophobic integral membrane proteins and its utility for membrane proteomics using microcapillary liquid chromatography coupled on-line with tandem mass spectrometry (microLC-MS/MS) is described. The present technique does not rely on the use of detergents, strong organic acids or cyanogen bromide-mediated(More)