On-target deuteration for peptide sequencing by laser mass spectrometry
摘要:
AbstractHydrogen–deuterium exchange was evaluated as a tool for sequence analysis of peptides by matrix‐assisted laser desorption–ionization utilizing post‐source decay (PSD‐MALDI). The number of exchangeable hydrogens (EH) of precursor ions and product ions can be determined from the mass difference between ion signals originating from the deuterated and the non‐deuterated form of a peptide, resulting in a second dimension of structural information. The reliability of sequence determination by combinatorial algorithms or pattern recognition techniques is considerably increased by employng this ‘EH spectroscopy.’ On‐target deuteration is a simple preparatory step which can be performed reversibly with the already mass‐analysed sample within a few minutes and without consumption of additional sample material. The efficiency of hydrogen–deuterium exchange with this technique is about 98.5%. In addition to supporting sequence analysis, deuteration can be used to investigate fundamental fragmentation mechanisms of peptides in PSD‐MALDI. Inconsistencies with expected fragmentation pathways have been found for fragments a1–a3 of substance P.
Strained alkynes derived from 2,2′-dihydroxy-1,1′-biaryls; synthesis and copper-free cycloaddition with azides
作者:Alessandro Del Grosso、Lavrentis-Dimitrios Galanopoulos、Cookson K. C. Chiu、Guy J. Clarkson、Peter B. O′ Connor、Martin Wills
DOI:10.1039/c7ob00991g
日期:——
A series of strained alkynes were prepared from 2,2′-dihydroxy-biaryls. Several were characterised by X-ray crystallography, revealing strained C(sp)–C(sp)–C(sp3) bond angles in the range of 163–167°. Their cycloadditions with azides proceed without a catalyst. Functionalised versions of these reagents have potential applications to materials synthesis and bioconjugations.
The specificity and mode of action of penicillolysin, a metalloproteinasefromPenicilliumcitrinum, were investigated with several bioactive-oligopeptides. The enzyme showed a high affinity toward the Pro-X (X = Gln, Lys, Leu or Arg) bonds of substance P, dynorphin A (1-13), neurotensin and chicken brain pentapeptide, and the R-R bonds in dynorphin A and neurotensin. Preferential cleavage of bonds
用几种生物活性寡肽研究了青霉素(一种来自柑橘青霉的金属蛋白酶)的特异性和作用方式。该酶对 P 物质、强啡肽 A (1-13)、神经降压素和鸡脑五肽的 Pro-X(X = Gln、Lys、Leu 或 Arg)键以及强啡肽 A 和神经降压素中的 RR 键显示出高亲和力. 在使用的肽上观察到在 P1 位置具有疏水性氨基酸残基的酶优先裂解键。青霉素溶菌素的特异性不同于其他金属蛋白酶。M(r) 和 pI 分别确定为 18,000 和 9.6。N 端区域的前 50 个氨基酸是 TKETCNASRKSALEKALSNTVKLANAAATAARSGSASKFSEYEKTTSSS。研究了青霉素溶菌素全酶和脱辅基酶的 CD 光谱。
Binding of Cu<sup>+</sup>and Cu<sup>2+</sup>with peptides: Peptides = oxytocin, Arg<sup>8</sup>-vasopressin, bradykinin, angiotensin-I, substance-P, somatostatin, and neurotensin
作者:Thankan Jayasekharan、Shyam L. Gupta、Vikas Dhiman
DOI:10.1002/jms.4062
日期:2018.4
these small peptides signifies that the bonding characteristics of both Cu+ and Cu2+ are different. The amino acid residues responsible for the binding of both Cu+ and Cu2+ in these peptides have been identified based on the density functional theory computed binding energy values of Cu+ and the fragment transformation method predicted binding preference of Cu2+ for individual amino acids.
7种天然肽的内在结合能力(催产素,精氨酸8 -加压素,缓激肽,血管紧张素I,P物质,促生长素抑制素,神经降压素和)与铜在2个不同的氧化态(铜I / II衍生自)不同的Cu + /已经研究了2+种前体来源的电荷依赖性结合特征。[M-(n -1)H + nC u I ]和[M-(2 n -1)H + nC u II ]肽-Cu I / II复合物是通过肽与CuI溶液/ Cu靶和CuSO 4解决方案,并通过使用基质辅助激光解吸/电离(MALDI)飞行时间质谱进行分析。[M-(n -1)H + nC u I ]和[M-(2 n -1)H + nC u II ]络合物的MALDI质谱均未显示质量损失,这是由于通过Cu +和Cu 2+去质子化作用,这些肽的主链─NH 。测得的m / z值表明在MALDI过程中Cu I / II氧化态还原为Cu 0。Cu +的数量和相对丰度与Cu 2+结合的肽相比,与肽结合的肽更大。催产素,arg
An Ionic Liquid Medium Enables Development of a Phosphine-Mediated Amine–Azide Bioconjugation Method
作者:Hisham M. El-Shaffey、Elizabeth J. Gross、Yvonne D. Hall、Jun Ohata
DOI:10.1021/jacs.1c06092
日期:2021.8.25
biomolecule labeling in aqueous media, the development of nonaqueous, biomolecule-compatible media for bioconjugation has significantly lagged behind. In this report, we demonstrate that an aprotic ionic liquid serves as a novel reaction solvent for protein bioconjugation without noticeable loss of the biomolecule functions. The ionic liquid bioconjugation approach led to discovery of a novel triph
Conjugates of disorazoles and their derivatives with cell-binding molecules, novel disorazole derivatives, processes of manufacturing and uses thereof
申请人:AEterna Zentaris GmbH
公开号:EP1900742A1
公开(公告)日:2008-03-19
The present invention provides conjugates of disorazoles and their derivatives with cell-binding molecules, such as peptides, proteins, hormones, blood proteins and antibodies. The present invention further provides novel disorazole derivatives and processes of manufacturing such conjugates and disorazole derivatives. These compounds can be used as medicaments for the treatment of physiological and/or pathophysiological conditions in mammals, in particular for the treatment of various tumors.