Kinetic Analysis of L-Carnosine Formation by β-Aminopeptidases
作者:Tobias Heck、Venkata S. Makam、Jochen Lutz、Lars M. Blank、Andreas Schmid、Dieter Seebach、Hans-Peter E. Kohler、Birgit Geueke
DOI:10.1002/adsc.200900697
日期:2010.2.15
investigated the kinetics of the enzyme-catalyzed peptidecouplings. DmpA catalyzed the formation of L-carnosine from C-terminally activated β-alanine derivatives (acyldonor) and L-histidine (acyl acceptor) in an aqueous reaction mixture at pH 10 with high catalytic rates (Vmax=19.2 μmol min−1 per mg of protein, kcat=12.9 s−1), whereas Vmax in the BapA-catalyzed coupling reaction remained below 1.4 μmol min−1
β,α-二肽L-肌肽高浓度存在于长寿的受神经支配的哺乳动物组织中,并作为食品添加剂被广泛出售。通过化学合成方法可大规模生产左旋肌肽。我们已经建立了两个水性酶促反应体系,用于使用人鞭毛支原体中溶解的细菌β-氨基肽酶DmpA和鞘翅目的鞘氨醇鞘氨醇的BapA作为催化剂制备L-肌肽,并研究了酶催化的肽偶联的动力学。DMPA催化L-肌肽的来自C末端活化的β丙氨酸衍生物在含水反应混合物中形成(酰基供体)和L-组氨酸(酰基受体)在pH 10下具有高催化速率(V最大= 19.2微摩尔分钟每mg蛋白质-1,k cat = 12.9 s -1),而BapA催化的偶联反应中的V max仍低于1.4μmolmin -1每mg蛋白质(k cat = 0.87 s -1)。尽管该反应的平衡位于水解产物的一边,但是该反应处于动力学控制下,L-肌肽暂时累积至对应于所用酰基供体的大于50%的产率的浓度。但是,竞争性亲核试剂
Synthetic mimics of mammalian cell surface receptors: method and compositions
申请人:Peterson Blake R.
公开号:US20100029906A1
公开(公告)日:2010-02-04
The present invention relates to new synthetic receptors. More particularly, the present invention relates to the use of the synthetic receptors for delivering a protein, peptide, drug, prodrug, lipid, nucleic acid, carbohydrate or small molecule into a target cell via receptor-mediated endocytosis. According to the invention, novel synthetic mimics of cell surface receptors have been designed and methods for use of the same are disclosed.
Stability of Fused Rings in Metal Chelates. XI. Stability of Dipeptide Amide-Copper(II) Complexes
作者:Osamu Yamauchi、Yasuo Nakao、Akitsugu Nakahara
DOI:10.1246/bcsj.46.3749
日期:1973.12
The structure-stability relationship between the copper(II) complexes of several dipeptide amides consisting of glycine and/or β-alanine has been investigated by potentiometric titration. The amides of glycylglycine, glycyl-β-alanine, and β-alanylglycine (abbreviated as H2L) have been found to form complexes of the type Cu(H2L)2+ with logK1 values 4.80–5.22. The −logKC1 values for deprotonation of