Determination of cysteine in pharmaceuticals via liquid chromatography with postcolumn derivatization

Jenke, Dennis R.; Brown, David Stanley

doi:10.1021/ac00138a007

Cited by 28 publications

(5 citation statements)

References 30 publications

(21 reference statements)

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“…Disulfide bond formation occurred spontaneously, because the distance between the two engineered cysteine residues was very close in the AD conformation (Figure 4a right, AD(Cys)). We confirmed this disulfide bonding by using 5,5 -dithiobis-(2-nitrobenzoic acid) spectrophotometric quantitation analysis [43]. As shown in Figure 4b right, no significant change in CD spectrum was observed at higher temperatures for AD(Cys).…”

Section: Stabilization Of Isolated Hsp60 Adsupporting

confidence: 62%

Human Molecular Chaperone Hsp60 and Its Apical Domain Suppress Amyloid Fibril Formation of α-Synuclein

Yamamoto

Fukui

Adachi

et al. 2019

IJMS

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Heat shock proteins play roles in assisting other proteins to fold correctly and in preventing the aggregation and accumulation of proteins in misfolded conformations. However, the process of aging significantly degrades this ability to maintain protein homeostasis. Consequently, proteins with incorrect conformations are prone to aggregate and accumulate in cells, and this aberrant aggregation of misfolded proteins may trigger various neurodegenerative diseases, such as Parkinson’s disease. Here, we investigated the possibilities of suppressing α-synuclein aggregation by using a mutant form of human chaperonin Hsp60, and a derivative of the isolated apical domain of Hsp60 (Hsp60 AD(Cys)). In vitro measurements were used to detect the effects of chaperonin on amyloid fibril formation, and interactions between Hsp60 proteins and α-synuclein were probed by quartz crystal microbalance analysis. The ability of Hsp60 AD(Cys) to suppress α-synuclein intracellular aggregation and cytotoxicity was also demonstrated. We show that Hsp60 mutant and Hsp60 AD(Cys) both effectively suppress α-synuclein amyloid fibril formation, and also demonstrate for the first time the ability of Hsp60 AD(Cys) to function as a mini-chaperone inside cells. These results highlight the possibility of using Hsp60 AD as a method of prevention and treatment of neurodegenerative diseases.

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Section: Stabilization Of Isolated Hsp60 Adsupporting

confidence: 62%

Human Molecular Chaperone Hsp60 and Its Apical Domain Suppress Amyloid Fibril Formation of α-Synuclein

Yamamoto

Fukui

Adachi

et al. 2019

IJMS

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“…[47][48][49] UV absorption was determined in a Hitachi U2810 photometer by using microcuevettes (50 mL; Binninger Analytik, Schwäbisch Gmünd, Germany). Unmodified or caged M.SssI (10 mm) was incubated with DTNB in DMSO (10 mm) for 10 min.…”

mentioning

confidence: 99%

Reversible Inactivation of the CG Specific SssI DNA (Cytosine‐C5)‐Methyltransferase with a Photocleavable Protecting Group

et al. 2007

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Caging of proteins by conjugation with a photocleavable group is a powerful approach for reversibly blocking enzymatic activity. Here we describe the covalent modification of the bacterial SssI DNA methyltransferase (M.SssI) with the cysteine-specific reagent 4,5-dimethoxy-2-nitrobenzylbromide (DMNBB). M.SssI contains two cysteine residues; replacement of the active-site Cys141 with Ser resulted in an approximately 100-fold loss of enzymatic activity; this indicates an important role for this residue in catalysis. However, replacement of Cys368 with Ala did not affect methyltransferase activity. Treatment of the Cys368Ala mutant enzyme with DMNBB led to an almost complete loss of activity. Irradiation of the inactivated enzyme with near-ultraviolet light (320-400 nm) restored 60 % of the catalytic activity. This indicates that caging by DMNBB can be used for the reversible inactivation of M.SssI.

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“…After cleavage of the disulfide with DTT, the monolayer, now presumably covered with SH groups, was exposed to solutions of DTNB, N -(1-pyrene)maleimide, or BODIPY. DTNB, which is also known as Ellman's reagent, is widely used for colorimetric determination of the SH group in proteins . However, it did not bind to the putative thiol-terminated SAM.…”

Section: Resultsmentioning

confidence: 99%

Formation, Characterization, and Sub-50-nm Patterning of Organosilane Monolayers with Embedded Disulfide Bonds: An Engineered Self-Assembled Monolayer Resist for Electron-Beam Lithography

Wang

Ramasubramaniam

et al. 2003

Langmuir

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This paper describes self-assembled monolayers (SAMs) that contain embedded disulfide bonds and the selective cleavage of the disulfides by electron-beam lithography (EBL). Phenyl(3-trimethoxysilylpropyl)disulfide (I) forms siloxane SAMs with a root-mean-square roughness of 1.8 Å. The disulfide bonds in I remain intact in the SAM and can react with dithiothreitol after monolayer formation, forming surface thiols, which can be derivatized with maleimide dyes. Atomic force microscopy (AFM) anodization and EBL have been used to create high-resolution patterns on the disulfide-containing monolayer. AFM anodization on monolayer I achieves 20-nm resolution lines with both topographic and chemical alterations in the patterned region. EBL with an accelerating voltage of 30 kV generates trenches 3-4 Å deep and 30 nm wide. According to AFM topographic and friction images, X-ray photoelectron spectroscopy damage simulation, and chemical rebinding tests, the chemical changes induced by EBL are consistent with cleavage of the disulfide bonds to form sulfhydryl groups. The resulting chemical patterns can be further developed by reaction with N-(1-pyrene)maleimide.

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Determination of cysteine in pharmaceuticals via liquid chromatography with postcolumn derivatization

Cited by 28 publications

References 30 publications

Human Molecular Chaperone Hsp60 and Its Apical Domain Suppress Amyloid Fibril Formation of α-Synuclein

Human Molecular Chaperone Hsp60 and Its Apical Domain Suppress Amyloid Fibril Formation of α-Synuclein

Reversible Inactivation of the CG Specific SssI DNA (Cytosine‐C5)‐Methyltransferase with a Photocleavable Protecting Group

Formation, Characterization, and Sub-50-nm Patterning of Organosilane Monolayers with Embedded Disulfide Bonds: An Engineered Self-Assembled Monolayer Resist for Electron-Beam Lithography

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