24118-03-4Relevant academic research and scientific papers
Measuring cell holding mechanism, and, a biosensor
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, (2007/10/06)
A measuring cell holding mechanism, comprising a measuring cell which is configured to include a dielectric block in which a flat face on which a ligand to be attached is formed, and a flow path member which constitutes a flow path between it and this flat face; a dielectric block pressing member which presses the dielectric block from the flow path member side; and a flow path member pressing member which presses the flow path member from the side opposite from the side on which the dielectric block is disposed, with a pressing force smaller than that by the dielectric block pressing member.
Protein backbone modification by novel C(α)-C side-chain scission
Ranganathan,Vaish,Shah
, p. 6545 - 6557 (2007/10/02)
α-Ketoamide (-NH-CO-CO-) units in intact peptides are generated from Ser/Thr residues via Ru(VIII)-catalyzed C(α)-C side-chain scission. Facets associated with this novel α-carbon modification have been probed with 75 peptides chosen to represent every possible peptide environment. The reactions were carried out at room temperature with in situ generated Ru(VIII) in biphasic (CH3CN/CCl4/pH 3 phosphate buffer, 1:1:2 v/v) medium. Whereas Ser/Thr residues placed at the C-terminal end in peptides undergo N-C bond scission leading to des-Ser/Thr peptide amides - thus acting as Gly equivalents in simulating the α-amidating action of pituitary enzymes - those located at the N-terminal or nonterminal or even at the C-terminal position (protected as amide) were found to undergo oxidative C-C bond scission (involving C(α) and C side-chain bond), resulting in the generation of α-ketoamide (-NH-CO-CO-) units in the intact peptide backbone. The difference in the products arising from C(α)-C side-chain scission of Ser/Thr esters and amides is rationalized on the basis of a common mechanism involving either oxaloesters [PeP-NH-CO-COX; X = OMe] or oxalamides [X = NH2 or NH-Pep] arising from the oxidation of initially formed carbinolamide intermediates [Pep-NH-CH(OH)-COX], wherein, while the former are shown to undergo hydrolysis to terminal amides [Pep-NH2], the oxalamides are found to be stable to hydrolysis. Ancillary noteworthy findings are those of peptide bond scission when contiguous Ser-Ser/Thr-Thr residues are present and the oxidative cleavage at C-terminal Tyr/Trp sites generating des amides. The oxidative methodology presented here is mild, simple, and practical and proceeds with chiral retention. The insensitivity of a large number of amino acid residues, such as Gly, Ala, Leu, Asn, Gln, Asp, Glu, Pro, Arg, Phe, Lys, Val, and Aib, and N-protecting groups, such as Boc, Z, and Bz, toward Ru(VIII) under the experimental conditions should make this methodology practical and useful. Sulfur-containing amino acids Cys and Met get oxidized to sulfones in the products.
SYNTHESIS OF A NEW CYCLIC ANALOGUE OF LULIBERIN
Nikolaev, S. V.,Burov, S. V.,Bakharev, V. D.,Makusheva, V. P.,Korkhov, V. V.
, p. 686 - 690 (2007/10/02)
A new cyclic analogue of luliberin possessing the capacity for stimulating ovulation in sexually mature and infantile rate and also exhibiting a pronounced prolongation of its influence on a number of behavioral reactions of animals has been synthesized.
SYNTHESIS OF BIOLOGICALLY ACTIVE ANALOGS OF LULIBERIN WITH SHORTENED AMINO ACID SEQUENCES
Burov, S. V.,Nikolaev, S. V.,Smironova, M. P.,Lupanova, G. E.,Bobrov, Yu. F.,et al.
, p. 732 - 737 (2007/10/02)
Two new analogs of the releasing factor of the luteinizing hormone with shortened amino acid sequences have been synthesized by the methods of classical peptide chemistry.The influence of the preparations on the action of chorionic gonadotropin and on the
SYNTHESIS OF 3(NH2); Pro3; D-Ala6>- and 2(NO2); Pro3; D-Ala6>LULIBERINS
Burov, S. V.,Kaurov, O. A.,Martynov, V. F.,Smirnova, M. P.
, p. 518 - 524 (2007/10/02)
In order to study the influence of substituents of the aromatic ring of D-phenylalanine on the inhibiting capacity of luliberian analogs, we have synthesized two new analogs: 2; Pro3; D-Ala6>- and
