252Cf Plasma Desorption Mass Spectrometry Research Articles

Rapid identification of calbindin-D28k cyanogen bromide peptide fragments by plasma desorption mass spectrometry.

Chicken intestinal calbindin-D28k is an intracellular protein which is believed to have a fundamental role in vitamin D-mediated transport of calcium. A mapping approach based on 252Cf plasma desorption mass spectrometry (PD mapping) was used to screen the DNA-deduced sequence of calbindin-D28k for sequence changes and post-translational modifications. In the PD mapping experiment, purified calbindin-D28k was cleaved with cyanogen bromide and the resulting peptides were subjected to PD mass spectrometric analysis either as a mixture or as high-performance liquid chromatography isolated fractions. The DNA-derived primary structure of calbindin-D28k was confirmed by rapid PD mass spectral identification of the CNBr peptide fragments, and the nature of the N-terminal blocking group was readily determined to be an acetyl group. The relatively non-destructive nature of the PD mass spectrometric analysis allowed the mapping of the N-terminal peptide through an additional in situ V8 protease enzymatic reaction.

Influence of sample concentration and adsorption time on the yield of biomolecule ions in plasma desorption mass spectrometry.

The yield of intact ions formed in 252Cf plasma desorption mass spectrometry has been investigated by analyzing melittin and bovine trypsin at different concentrations on a nitrocellulose surface. The yield of trypsin ions is shown to vary with the protein concentration and adsorption time. The singly charged ion of trypsin is observed when concentrated solution (10 microM to 1 mM) of bovine trypsin are applied for sufficient time.

Characterization and sequencing of normal and modified oligonucleotides by 252Cf plasma desorption mass spectrometry.

Plasma desorption (PD) mass spectra of normal deoxyribo-oligonucleotides and of neutral methylphosphonate deoxyribo-oligonucleosides are examined and discussed. Molecular ions of oligonucleotides up to nonamer have been observed for neutral species. It is also shown that PD mass spectra can be used to monitor chemical modifications of oligonucleotides, such as the covalent binding of an organic fluorescent probe, along the synthesis process.

Synthesis and characterization of carbohydrate-insulin conjugates using desorption ionization mass spectrometry

Blood glycoproteins containing terminal non-reducing D-galactosyl groups have previously been shown to be rapidly cleared from the circulatory system of animals. This occurs by interaction at the asialoglycoprotein receptor of the hepatocytes. We prepared several carbohydrate–insulin conjugates, containing one or more terminal D-galactosyl residues, to study their binding to this receptor. Fast atom bombardment (FAB) and 252Cf plasma desorption (PD) mass spectrometry were used to characterize the conjugates formed when insulin was treated with N-hydroxysuccinimide lactobionate. The synthetic approach, using N-hydroxysuccinimide amino acid esters, is a well-known procedure for peptide synthesis. However, the coupling reaction did not yield the expected lactobionyl insulin products. Instead, each lactobionyl group was accompained by an additional mass increment (115 daltons) in the conjugate structure. PD mass spectrometry verified that the products were intact modified insulins, while FAB mass spectrometry, with computerized peak matching and tandem mass spectrometry, provided the exact mass and structure of the additional mass increment. The two desorption ionization methods provided complementary data enabling the rapid characterization of these unexpected synthetic products.

Identification of dekamycin antibiotics

Dekamycin was isolated from strain DK 5 of Streptomyces fradiae, and purified by ion-exchange column chromatography. Excellent separation of N-acetylated derivatives of the antibiotic mixture was achieved by two different methods, flash chromatography and high-performance liquid chromatography. Mass spectrometry ( 252Cf plasma desorption mass spectrometry, fast atom bombardment) for the analytsis of N-acetyldekamycins (neomycin B, neomycin C, neamine and ribostamycin) was mainly used to confirm the molecular weight of a structure deduced by 1H and 13C NMR analyses.

Peptide and protein mapping by 252Cf-plasma desorption mass spectrometry

The mapping of peptide digests by using fast atom bombardment mass spectrometry for evaluating the correctness of known or expected protein sequences is a well-established strategy. A similar approach (“PD mapping”) is described which utilizes 252Cf-plasma desorption mass spectrometry (PDMS). This PD mapping approach is demonstrated and evaluated by screening the DNA-deduced sequences of recombinant interleukin-2 and human growth hormone. In the PD mapping experiment, the protein is cleaved either chemically or enzymatically and the molecular weights of the peptides predicted from the proposed amino acid sequence are compared with those determined mass spectrometrically. The relatively nondestructive nature of the PD mass spectrometric analysis allows further confirmation of the sequence assignments of individual peptides through additional steps of enzymatic or chemical modification on the nitrocellulose-bound peptides. The PD mapping method is both fast and sensitive, requiring only low nanomole amounts per map.

252Cf-Plasma desorption mass spectrometry using polymer surfaces

The adsorption of molecules onto a specially designed polymer surface is a new sample preparation technique for 252Cf-plasma desorption mass spectrometry ( 252Cf-PDMS) where an analyte is adsorbed from a solution onto the surface of a thin film that has been modified to have a particular attraction for the analyte. The adsorbed layer is directly analyzed by 252Cf-PDMS. Mass spectra of pepsin (mol. wt. 35 000) adsorbed onto nitrocellulose and highly-charged heparin fragments adsorbed onto an immobilized cationic surfactant film are some of the recent applications to difficult analytical problems.

Evaluation of secondary ion beam transport properties in plasma desorption mass spectrometry

The properties of a time of flight system for 252Cf plasma desorption mass spectrometry were evaluated by computer simulation. Among the different factors that contribute to mass resolution and detection efficiency of the secondary ions, geometrical misalignments and electric field inhomogeneities are discussed.

4,5-methylenedithio-4′,5′-propylenedithiotetrathiafulvalene (MPT) and 4,5-ethylenedithio-4′,5′-propylenedithiotetrathiafulvalene (EPT)

Title electron donors, unsymmetrical analogs of Bis(ethylenedithio)tetrathiafulvalene, are synthesized. The utility of 252Cf Plasma Desorption Mass Spectrometry in the characterization and purity determinations is also reported.

Plasma desorption mass spectrometric analysis of oligonucleoside methylphosphonates

By means of 252Cf plasma desorption mass spectrometry, molecular ions have been obtained for both homo- and heterooligomeric nucleoside methylphosphonates. Further confirmation of structure has been obtained from the observed fragmentation patterns.

252Cf Plasma Desorption Mass Spectrometry: Recent Advances and Applications

252Cf plasma desorption mass spectrometry (PDMS) as utilized in the BIO-ION instruments is described. The sensitivity of the technique is investigated for varying amounts of bovine insulin. The res...

Detection of trehalose monomycolate in Mycobacterium leprae grown in armadillo tissues.

Trehalose-6-monomycolate (TMM) was isolated from the lipids of armadillo-derived Mycobacterium leprae. Only meagre amounts of this glycolipid were recovered, but its structure was unequivocally established. Only alpha-mycolates were detected in the TMM by 252Cf plasma desorption mass spectrometry. Electron impact mass spectrometry showed the alpha branch to be principally C20. Trehalose dimycolate (cord factor) was not detectable. Since we have also found TMM in M. lepraemurium and in every Mycobacterium species so far examined, we suggest that this glycolipid is truly ubiquitous amongst mycobacteria.

Solid phase synthesis of somatostatin-28 II. A new biologically active octacosapeptide from anglerfish pancreatic islets

Somatostatin-28 II, an octacosapeptide recently isolated from anglerfish pancreatic islets, was synthetized by the solid phase method along with its somatostatin-14 II and somatostatin-28 II-(1–12) corresponding domains. Homogeneity of the synthetic peptides was demonstrated by analytical RP-HPLC, thin layer chromatography and electrophoresis. The peptides were further characterized by amino acids analysis, fast atomic bombarding mass spectrometry and/or 252Cf plasma desorption mass spectrometry. Synthetic somatostatin-28 II and somatostatin-14 II displace equally well the potent agonist (Tyr 0,D-Trp 8)-somatostatin-14 from its specific binding sites on anterior pituitary cells membranes. Both peptides activate adenylate cyclase from dispersed rat anterior pituitary cells.

ChemInform Abstract: The Use of a Stationary Cationic Surfactant as a Selective Matrix in 252Cf-Plasma Desorption Mass Spectrometry

Chemischer InformationsdienstVolume 17, Issue 34 Physical Organic Chemistry ChemInform Abstract: The Use of a Stationary Cationic Surfactant as a Selective Matrix in 252Cf-Plasma Desorption Mass Spectrometry C. J. MCNEAL, C. J. MCNEALSearch for more papers by this authorR. D. MACFARLANE, R. D. MACFARLANESearch for more papers by this author C. J. MCNEAL, C. J. MCNEALSearch for more papers by this authorR. D. MACFARLANE, R. D. MACFARLANESearch for more papers by this author First published: August 26, 1986 https://doi.org/10.1002/chin.198634057Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume17, Issue34August 26, 1986 RelatedInformation

The use of a stationary cationic surfactant as a selective matrix in 252Cf-plasma desorption mass spectrometry

The use of a stationary cationic surfactant as a selective matrix in 252Cf-plasma desorption mass spectrometry

Mass spectrometry of thermally unstable molecules. Evaluation of ionization techniques using glutamine as a reference compound

A limiting factor in the application of mass spectrometry to biochemically important molecules has been the inability to analyze compounds without inducing thermal decomposition. Glutamine, which readily cyclizes to 2-pyrrolidone-5-carboxylic acid with loss of ammonia, is one of the more difficult of these non-volatile, thermolabile biomolecules to determine. Using a heated, direct probe, no molecular ion for glutamine was observed with electron impact ionization. A protonated molecular ion was detected with direct probe chemical ionization and thermospray. In both cases, the major ion formed was derived from the thermolysis product, 2-pyrrolidone-5-carboxylic acid. Analysis by fast atom bombardment and 252Cf plasma desorption mass spectrometry yielded a molecular ion as base peak with a small ion from the 2-pyrrolidone-5-carboxylic acid. Ion evaporation produced only the molecular cations, and collisionally activated dissociation demonstrated that glutamine does not cyclize appreciably once protonated. These results suggest that glutamine can be used as a reference compound when analysis requires the optimization of conditions to produce a molecular ion. Furthermore, the relative intensity of the pyrolytic products, 2-pyrrolidone-5-carboxylic acid derived molecules, divided by the relative intensity of the molecular ions of glutamine provides a numerical evaluation of ionization conditions.

Combined thin layer chromatography/mass spectrometry: an application of 252Cf plasma desorption mass spectrometry for drug monitoring.

The pharmacokinetic analysis is performed in a three-step procedure: sample extraction, sample purification by thin layer chromatography (TLC) and quantitative sample detection by time-of-flight (TOF) mass spectrometry. 252Cf plasma desorption (PD) mass spectrometry utilizing the fission fragment-induced ionization and desorption of non-volatile compounds is suitable as a universal, non-destructive detector in TLC. Here TLC and mass spectrometry are operated in an off-line combination. As an example some pharmacokinetic data for etoposide (VP 16-213) together with calibration data are presented. The new experimental method is discussed in terms of sensitivity and detection limit.

252Cf-PDMS of chlorophyll photoreaction center models

Chemically modified chlorophylls and porphyrins have been studied by 252Cf-plasma desorption mass spectrometry (PDMS). The 252Cf-PDMS spectra of thin films show intense molecular ions and fragmentation from whicn we make reasonable assignments for compound identification. The 252Cf-PDMS of two compounds, bis(10-hydroxybutoxy-methyl pheophorbide a )-1,4-dichlorophtalate and linear bis(tetraphenylporphyrin) are discussed.

252Cf-plasma desorption mass spectrometry of covalently bound nucleic acid adducts: Psoralen-nucleosides photoadducts

Psoralen-nucleosides photocycloadducts have been studied by 252Cf-Plasma Desorption Mass Spectrometry. The present study involves isolation, high performance liquid chromatography purification and mass spectrometry analysis of the two major monoaddition products formed in the photoreaction of the naturally occurring 8-methoxypsoralen with thymidine. Structural informations have also been obtained concerning photocycloadducts of a new linear psoralen derivative 3-carbethoxypsoralen with thymidine and cytidine. A photobinding of 3-carbethoxypsoralen with adenosine has also been studied. The mass spectra of the adducts have been obtained directly without any derivatization. In all cases they showed molecular and quasimolecular ions in the positive and/or negative mode. It is concluded that 252Cf-PDMS is a powerful and easy technique for studying xenobiotic-modified nucleic acids.

The observation of quasi-molecular ions from a tiger snake venom component ( Mr 13 309) using 252Cf-plasma desorption mass spectrometry

A method involving fast heavy-ion bombardment of a solid sample called 252Cf-plasma desorption mass spectrometry has been used to study of a non-enzymatic, non-toxic phospholipase homolog from Australian tiger snake ( Notechis scutatus) venom. The protein consists of 119 amino acids in a single polypeptide chain cross-linked by 7 disulfide bridges. The isotopically averaged molecular mass as determined by protein sequence analysis is 13 309 atomic mass units (amu). The mass distributions were studied by means of time-of-flight measurements. Quasi-molecular ions associated to the molecule and its dimer were observed. The mass of the quasi-molecular ion corresponding to the molecule was determined to be 13 285 ± 25 amu.