Modification of ϵ‐amino group of lysine in proteins by acylation with pyromellitic dianhydride and <i>o</i>‐sulphobenzoic anhydride

Bagree, A.; Sharma, Indrajeet; Gupta, Komal; Narang, C.K.; Saund, A. K.; Mathur, Nupur

doi:10.1016/0014-5793(80)80315-2

Cited by 10 publications

(7 citation statements)

References 17 publications

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“…For the derivatization of alcohols we chose 2‐sulfobenzoic acid anhydride (Fig. 1(a)), a reagent known for the acylation of hydroxy compounds 21. The reagent combines both the well‐known reactivity of mixed anhydrides towards alcohols and the possibility of introducing a readily ionizable sulfonic acid group into the derivatized analyte molecule.…”

Section: Resultsmentioning

confidence: 99%

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Derivatization of small biomolecules for optimized matrix‐assisted laser desorption/ionization mass spectrometry

et al. 2002

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Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is a powerful tool for the measurement of low molecular mass compounds of biological interest. The limitations for this method are the volatility of many analytes, possible interference with matrix signals or bad ionization or desorption behavior of the compounds. We investigated the application of well-known and straightforward one-pot derivatization procedures to circumvent these problems. The derivatizations tested allow the measurement and the labeling of alcohols, aldehydes and ketones, carboxylic acids, alpha-ketocarboxylic acids and amines.

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Section: Resultsmentioning

confidence: 99%

“…Under the conditions used for derivatization, α‐amino groups of amino acids did not react with 2‐sulfobenzoic acid anhydride as exemplified for alanine (data not shown). Such a derivatization could be expected from the fact that the applied reagent is used in peptide chemistry for the derivatization of ε‐amino groups of lysine 21…”

Section: Resultsmentioning

confidence: 99%

Derivatization of small biomolecules for optimized matrix‐assisted laser desorption/ionization mass spectrometry

et al. 2002

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“…The sulfation indeed enhances sensitivity to steroids in ESI-MS, but has a disadvantage -the endogenous sulfated steroid must be completely removed from the sample before sulfation of the parental steroid, because it is impossible to distinguish between the chemically synthesized and endogenous sulfate. To avoid this problem, the use of 2-sulfobenzoic acid anhydride seems to be advantageous -the 2-sulfobenzoate is formed [21] (Fig. 3f).…”

Section: Derivatization For Negative Esi-msmentioning

confidence: 97%

Derivatization of neutral steroids to enhance their detection characteristics in liquid chromatography?mass spectrometry

Higashi

Shimada²

2004

Analytical and Bioanalytical Chemistry

175

136

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This review article underlines the detection-oriented derivatization of neutral steroids in liquid chromatography-mass spectrometry (LC-MS). Steroids have strong biological activity at very low concentrations in target tissues and, therefore, the analysis of steroids in body fluids or tissues is necessary to elucidate the nature of the many endocrine disease processes and thus be useful for diagnosis and treatment. LC-MS has recently been used for steroid analysis because of its specificity and versatility, but the ionization efficiencies of most steroids are relatively low for the different ionization methods. Derivatization enhances the ionization efficiencies of steroids, leading to high sensitivity and specific detection. For electrospray ionization MS the introduction of permanently charged moieties or easily ionizable moieties effectively increases the sensitivity of detection of steroids. The introduction of moieties with proton affinity or electron affinity enhances the analyte signals in positive and negative atmospheric pressure chemical ionization MS, respectively.

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“…Modification of the enzyme with cyclic anhydrides of phthalic (B), trimellitic (C), pyromellitic (D) and mellitic (E) acids was carried out according to a slightly modified procedure described in [36]. A solution (1 ml) of the anhydride (2 mM) in dimethylsulfoxide was added dropwise at 4°C to 10 nil 40 pM a-chymotrypsin in 0.1 M KH2P04 buffer (pH 8.0) with stirring.…”

Section: Modtfication Of A-chymotrypsinmentioning

confidence: 99%

Protein stabilization via hydrophilization

Mozhaev

Šikšnis

Melik‐Nubarov

et al. 1988

European Journal of Biochemistry

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This paper experimentally verifies the idea presented earlier that the contact of nonpolar clusters located on the surface of protein molecules with water destabilizes proteins. It is demonstrated that protein stabilization can be achieved by artificial hydrophilization of the surface area of protein globules by chemical modification. Two experimental systems are studied for the verification of the hydrophilization approach.1. The surface tyrosine residues of trypsin are transformed to aminotyrosines using a two-step modification procedure: nitration by tetranitromethane followed by reduction with sodium dithionite. The modified enzyme is much more stable against irreversible thermoinactivation: the stabilizing effect increases with the number of aminotyrosine residues in trypsin and the modified enzyme can become even 100 times more stable than the native one.2. a-Chymotrypsin is covalently modified by treatment with anhydrides or chloroanhydrides of aromatic carboxylic acids. As a result, different numbers of additional carboxylic groups (up to five depending on the structure of the modifying reagent) are introduced into each Lys residue modified. Acylation of all available amino groups of cr-chymotrypsin by cyclic anhydrides of pyromellitic and mellitic acids results in a substantial hydrophilization of the protein as estimated by partitioning in an aqueous Ficoll-400/Dextran-70 biphasic system. These modified enzyme preparations are extremely stable against irreversible thermal inactivation at elevated temperatures (65 -98 "C); their thermostability is practically equal to the stability of proteolytic enzymes from extremely thermophilic bacteria, the most stable proteinases known to date.Applications of enzymatic catalysis in biotechnology, fine organic synthesis, analysis, medicine, and other areas are often hindered because many enzymes, if isolated from their natural environment in vivo, become unstable and rapidly inactivate (denature); for review, see [l, 21. For these reasons the problem of enzyme stabilization has received considerable attention in recent years [3 -81.The analysis of the structure-stability relationships in the protein leads us to the conclusion [S] that the structure of proteins is not optimal with regard to their stability. There are still some reverses for stabilization which are used by nature for the production of extremely stable proteins, such as, for example, enzymes from thermophilic microorganisms ; for review, see [S, 91. Reserves of such a kind may be useful for artificial stabilization of enzymes. We shall discuss here, from this viewpoint, how to improve the protein structure in order to make enzymes more stable.According to X-ray crystallographic data, about one half of the surface area of proteins is occupied by nonpolar amino Corre2pondence to K. Martinek, Ustav OrganickC Chemie a Biochemie, Ceskoslovenska Akademie Vtid, Flemingovo nimEsti 2, CS-166-10 Praha, CzechoslovakiaThe authors wish to dedicate this paper to the memory of their teacher and friend. Professor...

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Modification of ϵ‐amino group of lysine in proteins by acylation with pyromellitic dianhydride and o‐sulphobenzoic anhydride

Cited by 10 publications

References 17 publications

Derivatization of small biomolecules for optimized matrix‐assisted laser desorption/ionization mass spectrometry

Derivatization of small biomolecules for optimized matrix‐assisted laser desorption/ionization mass spectrometry

Derivatization of neutral steroids to enhance their detection characteristics in liquid chromatography?mass spectrometry

Protein stabilization via hydrophilization

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