<sup>252</sup>Cf‐Plasma Desorption Mass Spectrometry

The cellulose-binding properties of the highly conserved terminal region which is common to several fungai ceUulases were studied. Domains were prepared by proteolytic cleavage of Trichoderma reesei CBH 1 and the corresponding enzyme from Sporotrichum pulverulentum, and a peptide corresponding to residues 462-497 (the C-terminal part) of Trichoderma CBH 1 was synthesized. The three peptides showed similar binding behavior, whereas reduced and S-carboxymethylated T. reesei fragment was inactive. This region thus appears to serve as an independent functional domain in which the C-terminal part is responsible for the binding, which in turn requires an intact three-dimensional structure.

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“…Plasma desorption mass spectrometry was carried out in a Bioion 20 instrument (Bioion Nordic, Uppssala) [19].…”

Section: Methodsmentioning

confidence: 99%

Isolated fungal cellulose terminal domains and a synthetic minimum analogue bind to cellulose

Johansson¹,

Ståhlberg²,

Lindeberg³

et al. 1989

FEBS Letters

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“…The pituitary was chosen as our first test tissue because this neuroendocrine gland contains peptides from several precursors with a variety of posttranslational modifications. Two different types of mass spectrometers were evaluated: a plasma desorption (PD)-MS instrument because of its wide mass range and excellent sensitivity (17)(18)(19) and a double-focusing magnetic sector field instrument with fast atom bombardment (FAB) ionization because of its mass accuracy (20,21 Packard 1090M work-station, a linear gradient of 0-50% (vol/vol) acetonitrile in 0.1% aqueous trifluoroacetic acid over 50 min, a flow rate of 1 ml/min, and detection at 215 nm (22). One-millimeter fractions were collected into 1.5-ml polypropylene tubes and dried in a vacuum centrifuge.…”

mentioning

confidence: 99%

Mass spectrometric charting of bovine posterior/intermediate pituitary peptides.

Feistner

Højrup

Evans

et al. 1989

Proc. Natl. Acad. Sci. U.S.A.

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The feasibility for charting neuropeptides in neuroendocrine tissues on the basis of the universal property and inherent specificity of their molecular weights was explored. As a model, a comprehensive MS analysis ofextractable peptides from bovine posterior/intermediate pituitary was performed. Two suitable MS techniques-namely, plasmadesorption time-of-flight and fast atom bombardment MSwere evaluated, and each method could identify more than 20 peptides, including N-terminally acetylated and C-terminally amidated species. In toto these peptides account for almost the entire lengths of propressophysin, prooxyphysin, and proopiomelanocortin. Some of the experimentally determined molecular weights did not match any known peptides. Three of these species were identified as acidic joining peptide(4-24)

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“…Mass spectrometry. Mass determination was carried out by plasma desorption [16] or by matrix-assisted laser desorption mass spectrometry [17]. Plasma desorption analysis was performed with a BioIon 20 instrument (BioIon Nordic AB, Sweden) and matrix-assisted laser desorption was performed with a Kratos Compact Maldi I1 instrumtent (Kratos Analytical, England) using a-cyano-4-hydroxycinnamic acid as the matrix.…”

Section: Methodsmentioning

confidence: 99%

Role of Arginine Residues for the Activity of Fasciculin

Červeñanský¹,

Engström²,

Karlsson³

1995

European Journal of Biochemistry

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The West African green mamba, Dendroaspis angusticeps, has two toxins, fasciculins, that are noncompetitive inhibitors of acetylcholinesterase. Arginine residues of fasciculin 2 were modified with 1,2-cyclohexanedione. Two of these residues, Arg24 and Arg37, reacted very slowly or not at all. Modification of Arg28 reduced the activity only by 13%. Argll and Arg27 are unique for fasciculins; a comparison of the sequences of 175 snake toxins homologous to fasciculins showed that no other toxin has arginine in the corresponding positions. Modification of the two unique arginines had a large effect and decreased the activity by 73% (Argll) and 85% (Arg27). This was apparently not due to structural perturbations, since the modification did not change the circular dichroic spectra. The two arginine residues probably participate in the binding to acetylcholinesterase. They are located on the same side of the toxin molecule and the distance between their a-carbons is 2.7 nm. This may indicate binding to sites that are far apart and suggests that fasciculin covers a large area of the enzyme.Keywords. Snake toxin ; fasciculin; arginine modification; acetylcholinesterase.The African snakes of the genus Dendroaspis (mambas) have neurotoxic venoms. A gel-filtration-purified fraction of Dendroaspis angusticeps (Western green mamba) venom produced hypersensitivity to touch and later long-lasting fasciculations in mice, i.e. uncontrolled muscle twitches, salivation, lacrimation, and secretion from the nose [l]. The symptoms indicated an elevated level of acetylcholine at the neuromuscular junction. It had been established that hypersensitivity was due to dendrotoxin, which had been isolated some years earlier [2]. Several dendrotoxins have been subsequently isolated from various mamba venoms. These toxins block voltage-gated potassium channels, which leads to increased release of acetylcholine [3]. The other symptoms observed in mice were typical for poisoning with anticholinesterases (AChE). This observation led to the isolation of two potent inhibitors of AChE. These inhibitors were called fasciculin 1 and 2, because of the symptoms theyThree fasciculins are known, fasciculin 1 and 2 from D. an- values in the range 10~"-10-'2 M [4, 6-11]. Other A C E are more than one million times less sensitive, e.g. AChE from chick biventer cervicis muscle and brain, cobra venom, and insects (heads of Musca dornestica, common house-fly) are inhibited with K, values greater than 10 pM. Butyrylcholinesterases are inhibited with K, values in the micromolar range, 0,5 pM for human serum cholinesterase [6-81.Fasciculins have many lysine and arginine residues giving the molecules a positive net charge at pH 7. Since many AChE inhibitors, e.g. neostigmine and physostigmine, are cationic molecules, it seems logical to investigate the role of amino and guanidino groups for the activity of fasciculin. Earlier [12], we acetylated amino groups of fasciculin 2 with acetic anhydride and isolated the mono acetyl derivatives. Modification of the a-amino g...

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²⁵²Cf‐Plasma Desorption Mass Spectrometry

Cited by 315 publications

References 134 publications

Isolated fungal cellulose terminal domains and a synthetic minimum analogue bind to cellulose

Isolated fungal cellulose terminal domains and a synthetic minimum analogue bind to cellulose

Mass spectrometric charting of bovine posterior/intermediate pituitary peptides.

Role of Arginine Residues for the Activity of Fasciculin

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252Cf‐Plasma Desorption Mass Spectrometry

Cited by 315 publications

References 134 publications

Isolated fungal cellulose terminal domains and a synthetic minimum analogue bind to cellulose

Isolated fungal cellulose terminal domains and a synthetic minimum analogue bind to cellulose

Mass spectrometric charting of bovine posterior/intermediate pituitary peptides.

Role of Arginine Residues for the Activity of Fasciculin

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Product

Resources

About

²⁵²Cf‐Plasma Desorption Mass Spectrometry