- Methods for 20S Immunoproteasome and 20S Constitutive Proteasome Determination Based on SPRI Biosensors
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The 20S proteasome, released into the circulation, is a novel cancer biomarker. It exists in two forms: the constitutive proteasome (20Sc) and the immunoproteasome (20Si), which both have separate diagnostic significance. The aim of this work was to develop new methods for 20Si and 20Sc determination. Five alternative specific biosensors usable with the surface plasmon resonance imaging (SPRI) technique for 20Si determination have been developed. Specific 20Si entrapment on the biosensor surface from an analyzed solution was achieved by means of an immobilized specific 20Si receptor. Four of the biosensors contain newly synthesized specific 20Si receptors, while the fifth contains the inhibitor ONX 0914. A method for 20Sc determination using an SPRI biosensor containing PSI inhibitor has been developed. By the introduction of an inhibitor blocking 20Si, 20Sc is selectively determined. All of the methods developed for 20Si and 20Sc determination exhibit good selectivity and satisfactory precision, recoveries and dynamic response ranges. 20Si and 20Sc were determined in blood plasma samples from healthy donors and patients with acute leukemia. In the case of these patients 20Si was the major component, and its level was more than one order of magnitude higher than in the healthy donors.
- Anna, Sankiewicz,Agnieszka, Markowska,Zenon, Lukaszewski,Beata, Puzan,Ewa, Gorodkiewicz
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p. 174 - 185
(2017/03/22)
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- Biomimetic peptide bond formation in water with aminoacyl phosphate esters
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Aminoacyl phosphates, biomimetic analogues of aminoacyl adenylates, react efficiently with amino acid esters to form dipeptides with retention of stereochemical integrity. The reactions are selective and occur readily in the presence of nucleophiles other than amino groups on their side chains. Aminoacyl phosphate esters that lack an amino-protecting group are also suitable for peptide bond formation, leading to a simplified overall process.
- Dhiman, Raj S.,Opinska, Liliana Guevara,Kluger, Ronald
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supporting information; experimental part
p. 5645 - 5647
(2011/09/15)
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- Peptide bond formation by aminolysin-A catalysis: A simple approach to enzymatic synthesis of diverse short oligopeptides and biologically active puromycins
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A new S9 family aminopeptidase derived from the actinobacterial thermophile Acidothermus cellulolyticus was cloned and engineered into a transaminopeptidase by site-directed mutagenesis of catalytic Ser491 into Cys. The engineered biocatalyst, designated aminolysin-A, can catalyze the formation of peptide bonds to give linear homo-oligopeptides, hetero-dipeptides, and cyclic dipeptides using cost-effective substrates in a one-pot reaction. Aminolysin-A can recognize several C-terminal-modified amino acids, including the l- and d-forms, as acyl donors as well as free amines, including amino acids and puromycin aminonucleoside, as acyl acceptors. The absence of amino acid esters prevents the formation of peptides; therefore, the reaction mechanism involves aminolysis and not a reverse reaction of hydrolysis. The aminolysin system will be a beneficial tool for the preparation of structurally diverse peptide mimetics by a simple approach.
- Usuki, Hirokazu,Yamamoto, Yukihiro,Arima, Jiro,Iwabuchi, Masaki,Miyoshi, Shozo,Nitoda, Teruhiko,Hatanaka, Tadashi
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supporting information; experimental part
p. 2327 - 2335
(2011/05/02)
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- Biomimetic protecting-group-free 2′, 3′-selective aminoacylation of nucleosides and nucleotides
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Aminoacyl phosphate monoesters can be prepared free of an amino-protecting group and used directly in lanthanum-promoted selective monoacylation of either the 2′ or 3′-hydroxyl of nucleosides and nucleotides. For example, phenylalanyl ethyl phosphate rapi
- Her, Sohyoung,Kluger, Ronald
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supporting information; experimental part
p. 676 - 678
(2011/03/22)
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- Engineered transaminopeptidase, aminolysin-S for catalysis of peptide bond formation to give linear and cyclic dipeptides by one-pot reaction
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Aminopeptidase from Streptomyces thermocyaneoviolaceus NBRC14271 was engineered into transaminopeptidase and used to catalyze an aminolysis reaction to give linear and cyclic dipeptides from cost-effective substrates such as the ester derivatives of amino
- Usuki, Hirokazu,Uesugi, Yoshiko,Arima, Jiro,Yamamoto, Yukihiro,Iwabuchi, Masaki,Hatanaka, Tadashi
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supporting information; experimental part
p. 580 - 582
(2010/05/01)
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