Multiple binding sites for I-125 RTI-121 and other cocaine analogs in rat frontal cerebral cortex
Creator
Boja J W; Carroll F I; Vaughan R A; Kopajtic T; Kuhar M J
Publisher
Synapse
Date
1998
1998-09
Description
In an effort to identify novel binding sites for cocaine and its analogs, we carried out binding studies with the high-affinity and selective ligand [I-125]RTI-121 in rat frontal cortical tissue. Very low densities of binding sites were found. Saturation analysis revealed that the binding was to both high- and low-affinity sites. Pharmacological competition studies were carried out with inhibitors of the dopamine, norepinephrine, and serotonin transporters. The various transporter inhibitors inhibited the binding of 15 pM [I-125]RTI-121 in a biphasic fashion following a two-site binding model. The resultant data were complex and did not suggest a simple association with any single transporter. Correlational analysis supported the following hypothesis: [I-125] RTI-121 binds to known transporters and not to novel sites; these include dopamine, norepinephrine, and serotonin transporters. Immunoprecipitation of transporters photoaffinity labeled with [(125)] RTI-82 and subsequent analysis of SDS-page gels revealed the presence of authentic dopamine transporters in these samples; displacement of the photoaffinity label occurred with a typical dopamine transporter pharmacology. These data are compatible with the binding properties of RTI-181 and the presence of several known transporters in the tissue studied. Synapse 30:9-17, 1998. (C) 1998 Wiley-Liss, Inc.dagger
Type 2 diabetes mellitus (T2DM) is associated with oxidative stress and perturbed iron metabolism. Serotransferrin (Trf) and ceruloplasmin (Cp) are two key proteins involved in iron metabolism and anti-oxidant defense. Non-enzymatic glycation and oxidative modification of plasma proteins are known to occur under hyperglycemia and oxidative stress. In this study, shotgun proteomics and (2)H2O-based metabolic labeling were used to characterize post-translational modifications and assess the kinetics of Trf and Cp in T2DM patients and matched controls in vivo. Six early lysine (Amadori) and one advanced arginine glycation were detected in Trf. No glycation, but five asparagine deamidations, were found in Cp. T2DM patients had increased fractional catabolic rates of both Trf and Cp that correlated with HbA1c (p \textless 0.05). The glycated Trf population was subject to an even faster degradation compared to the total Trf pool, suggesting that hyperglycemia contributed to an increased Trf degradation in T2DM patients. Enhanced production of Trf and Cp kept their levels stable. The changes in Trf and Cp turnover were associated with increased systemic oxidative stress without any alteration in iron status in T2DM. These findings can help better understand the potential role of altered Trf and Cp metabolism in the pathogenesis of T2DM and other diseases.
Exome sequence identified a c.320A \textgreater G ALG13 variant in a female with infantile epileptic encephalopathy with normal glycosylation and random X inactivation: Review of the literature.
Creator
Hamici Sana; Bastaki Fatma; Khalifa Mohamed
Publisher
European journal of medical genetics
Date
2017
2017-10
Description
Congenital Disorders of Glycosylation (CDG) are new and rapidly expanding neurometabolic disorders with multisystem involvements, broad phenotypic manifestations, and variable severity. The majority results from a defect of one of the steps involved with protein or lipid N-glycosylation pathway. Almost all are inherited in autosomal recessive patterns with a few exceptions such as the
Glycation Reduces the Stability of ApoAI and Increases HDL Dysfunction in Diet-Controlled Type 2 Diabetes.
Creator
Kashyap Sangeeta R; Osme Abdullah; Ilchenko Serguei; Golizeh Makan; Lee Kwangwon; Wang Shuhui; Bena James; Previs Stephen F; Smith Jonathan D; Kasumov Takhar
Publisher
The Journal of clinical endocrinology and metabolism
Date
2018
2018-02
Description
Context: Hyperglycemia plays a key role in the pathogenesis of cardiovascular complications of diabetes. Type 2 diabetes mellitus (T2DM) is associated with high-density lipoprotein (HDL) dysfunction and increased degradation of apolipoprotein I (ApoAI). The mechanism(s) of these changes is largely unknown. Objective: To study the role of hyperglycemia-induced glycation on ApoAI kinetics and stability in patients with diet-controlled T2DM. Design: 2H2O-metabolic labeling approach was used to study ApoAI turnover in patients with diet-controlled T2DM [n = 9 (5 F); 59.3 +/- 8.5 years] and matched healthy controls [n = 8 (4 F); 50.7 +/- 11.6 years]. The effect of Amadori glycation on in vivo ApoAI stability and the antioxidant and cholesterol efflux properties of HDL were assessed using a proteomics approach and in vitro assays. Results: Patients with T2DM had increased turnover of ApoAI and impaired cholesterol efflux and antioxidant properties of HDL. Glycated hemoglobin was negatively correlated with the half-life of ApoAI and cholesterol efflux function of HDL. Proteomics analysis identified several nonenzymatic early (Amadori) glycations of ApoAI at lysine sites. The kinetics analysis of glycated and native ApoAI peptides in patients with T2DM revealed that glycation resulted in a threefold shorter ApoAI half-life. Conclusions: The 2H2O method allowed the detection of early in vivo impairments in HDL metabolism and function that were related to hyperglycemia-induced glycation of ApoAI in T2DM.
Differential glycosylation of the Cas-Br-E env protein is associated with retrovirus-induced spongiform neurodegeneration.
Creator
Lynch W P; Sharpe A H
Publisher
Journal of virology
Date
2000
2000-02
Description
The wild mouse ecotropic retrovirus, Cas-Br-E, induces progressive, noninflammatory spongiform neurodegenerative disease in susceptible mice. Functional genetic analysis of the Cas-Br-E genome indicates that neurovirulence maps to the env gene, which encodes the surface glycoprotein responsible for binding and fusion of virus to host cells. To understand how the envelope protein might be involved in the induction of disease, we examined the regional and temporal expression of Cas-Br-E Env protein in the central nervous systems (CNS) of mice infected with the highly neurovirulent chimeric virus FrCas(E). We observed that multiple isoforms of Cas-Br-E Env were expressed in the CNS, with different brain regions exhibiting unique patterns of processed Env glycoprotein. Specifically, the expression of gp70 correlated with regions showing microglial infection and spongiform neurodegeneration. In contrast, regions high in neuronal infection and without neurodegenerative changes (the cerebellum and olfactory bulb) were characterized by a gp65 Env protein isoform. Sedimentation analysis of brain region extracts indicated that gp65 rather than gp70 was incorporated into virions. Biochemical analysis of the Cas-Br-E Env isoforms indicated that they result from differential processing of N-linked sugars. Taken together, these results indicate that differential posttranslational modification of the Cas-Br-E Env is associated with a failure to incorporate certain Env isoforms into virions in vivo, suggesting that defective viral assembly may be associated with the induction of spongiform neurodegeneration.
Unique N-linked glycosylation of CasBrE Env influences its stability, processing, and viral infectivity but not its neurotoxicity.
Creator
Renszel Krystal M; Traister Russell S; Lynch William P
Publisher
Journal of virology
Date
2013
2013-08
Description
The envelope protein (Env) from the CasBrE murine leukemia virus (MLV) can cause acute spongiform neurodegeneration analogous to that induced by prions. Upon central nervous system (CNS) infection, Env is expressed as multiple isoforms owing to differential asparagine (N)-linked glycosylation. Because
Mild acidic pH inhibition of the major pathway of herpes simplex virus entry into HEp-2 cells.
Creator
Rosenthal K S; Killius J; Hodnichak C M; Venetta T M; Gyurgyik L; Janiga K
Publisher
The Journal of general virology
Date
1989
1989-04
Description
Penetration of the KOS strain of herpes simplex virus type 1 (HSV-1) and the MS and 333 strains of herpes simplex virus type 2 (HSV-2) into HEp-2 cells at pH 6.3 was at least 100-fold less efficient than at pH 7.4. Penetration of two low passage clinical isolates was completely blocked at pH 6.3. The syncytium-forming