Identification of disulfide bridges in a cardiotoxic peptide by electrospray ionization

1994 ◽  
Vol 23 (12) ◽  
pp. 719-726 ◽  
Author(s):  
Thaiya Krishnamurthy ◽  
Charles R. Hauer ◽  
M. Prabhakaran ◽  
James G. Freedy ◽  
Kyozo Hayashi
Keyword(s):  
Electrospray Ionization ◽  
Disulfide Bridges

Adsorption of Fibrinogen and Fragment D of Fibrinogen onto the Insolubilized αChain of Fibrin

1979 ◽  
Vol 41 (04) ◽  
pp. 687-690
Author(s):  
F R Matthias
Keyword(s):  
Disulfide Bridges ◽  
Soluble Fibrin ◽  
Immobilized Proteins ◽  
Covalently Bound

SummaryAfter thrombin treatment insolubilized fibrinmonomer, which is obtained from insolubilized fibrinogen covalently bound to agarose, adsorbs soluble fibrin and its derivatives from solutions. The immobilized proteins are attached to the agarose by the ‘A’ αchain. After reduction of the disulfide bridges the β and γchains can be removed from the agarose.After thrombin treatment the immobilized αchain adsorbs fibrinogen and fragment D. To some extent the β and γchain do not seem necessary for the adsorption. The amount adsorbed increases, when thrombin treatment of the insolubilized protein follows the reduction process.This may indicate that the fibrinopeptides ‘A’ of the insolubilized αchain are better accessible after the removal of the β and γchains.

Alkali Metal Cationization of Alkyl Glucosides under Electrospray Ionization Conditions

2005 ◽  
Vol 42 (4) ◽  
pp. 226-228 ◽  
Author(s):  
Joanna Zembrzuska ◽  
Agnieszka Zgoła-Grześkowiak ◽  
Magdalena Frańska
Keyword(s):  
Alkali Metal ◽  
Electrospray Ionization ◽  
Alkyl Glucosides

Intraoperative assessment of isocitrate dehydrogenase mutation status in human gliomas using desorption electrospray ionization–mass spectrometry

2020 ◽  
Vol 132 (1) ◽  
pp. 180-187 ◽  
Author(s):  
Clint M. Alfaro ◽  
Valentina Pirro ◽  
Michael F. Keating ◽  
Eyas M. Hattab ◽  
R. Graham Cooks ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Isocitrate Dehydrogenase ◽  
Tumor Resection ◽  
Desorption Electrospray Ionization ◽  
Extent Of Resection ◽  
Ionization Mass ◽  
Idh Mutation ◽  
Mutation Status ◽  
Desi Ms

OBJECTIVEThe authors describe a rapid intraoperative ambient ionization mass spectrometry (MS) method for determining isocitrate dehydrogenase (IDH) mutation status from glioma tissue biopsies. This method offers new glioma management options and may impact extent of resection goals. Assessment of the IDH mutation is key for accurate glioma diagnosis, particularly for differentiating diffuse glioma from other neoplastic and reactive inflammatory conditions, a challenge for the standard intraoperative diagnostic consultation that relies solely on morphology.METHODSBanked glioma specimens (n = 37) were analyzed by desorption electrospray ionization–MS (DESI-MS) to develop a diagnostic method to detect the known altered oncometabolite in IDH-mutant gliomas, 2-hydroxyglutarate (2HG). The method was used intraoperatively to analyze tissue smears obtained from glioma patients undergoing resection and to rapidly diagnose IDH mutation status (< 5 minutes). Fifty-one tumor core biopsies from 25 patients (14 wild type [WT] and 11 mutant) were examined and data were analyzed using analysis of variance and receiver operating characteristic curve analysis.RESULTSThe optimized DESI-MS method discriminated between IDH-WT and IDH-mutant gliomas, with an average sensitivity and specificity of 100%. The average normalized DESI-MS 2HG signal was an order of magnitude higher in IDH-mutant glioma than in IDH-WT glioma. The DESI 2HG signal intensities correlated with independently measured 2HG concentrations (R2 = 0.98). In 1 case, an IDH1 R132H–mutant glioma was misdiagnosed as a demyelinating condition by frozen section histology during the intraoperative consultation, and no resection was performed pending the final pathology report. A second craniotomy and tumor resection was performed after the final pathology provided a diagnosis most consistent with an IDH-mutant glioblastoma. During the second craniotomy, high levels of 2HG in the tumor core biopsies were detected.CONCLUSIONSThis study demonstrates the capability to differentiate rapidly between IDH-mutant gliomas and IDH-WT conditions by DESI-MS during tumor resection. DESI-MS analysis of tissue smears is simple and can be easily integrated into the standard intraoperative pathology consultation. This approach may aid in solving differential diagnosis problems associated with low-grade gliomas and could influence intraoperative decisions regarding extent of resection, ultimately improving patient outcome. Research is ongoing to expand the patient cohort, systematically validate the DESI-MS method, and investigate the relationships between 2HG and tumor heterogeneity.

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