caa a22 4500 477127029 CHVBK 20180405111652.0 cr unu---uuuuu 170330e19971001xx s 000 0 eng 10.1023/A:1012120705408 doi (NATIONALLICENCE)springer-10.1023/A:1012120705408 Protection Afforded by Maltosyl-β-cyclodextrin Against α-Chymotrypsin-Catalyzed Hydrolysis of a Luteinizing Hormone-Releasing Hormone Agonist, Buserelin Acetate [Elektronische Daten] [Kazutaka Matsubara, Yukihiro Ando, Tetsumi Irie, Kaneto Uekama] Purpose. The present study addresses how maltosyl-β-cyclodextrin (G2-β-CyD) impacts upon the α-chymotrypsin-catalyzed hydrolysis of buserelin acetate, an agonist of luteinizing hormone-releasing hormone with emphasis upon the direct effect of G2-β-CyD on the activity of the protease. Methods. Kinetic and solubility studies were performed in isotonic phosphate buffer (pH 7.4) at 25°C and 37°C. The interaction of α-chymotrypsin with G2-β-CyD in the buffer solution was examined by differential scanning calorimetry. Results. G2-β-CyD decelerated the α-chymotrypsin-catalyzed hydrolysis of buserelin acetate to give the 1−3 tripeptide and the 4−9 hexapeptide fragments. This deceleration can be explained solely by a nonproductive encounter between a complex of the substrate with G2-β-CyD and the protease at relatively low CyD concentrations, while the direct inhibitory effect of G2-β-CyD on the proteolytic activity made a considerable contribution to the overall deceleration of the hydrolysis at higher CyD concentrations. Calorimetric studies indicate the presence of intermediate states in the thermal unfolding of α-chymotrypsin, simultaneously accompanied by the autolysis. By contrast, a two-state thermal unfolding of α-chymotrypsin was observed in the presence of G2-β-CyD, suggesting reduced proteolytic activity upon binding to G2-β-CyD. Conclusions. These results suggest that G2-β-CyD at higher concentrations inhibits the proteolytic action of α-chymotrypsin through direct interaction with the protease, as well as through the formation of a non-productive complex with the substrate. Plenum Publishing Corporation, 1997 buserelin acetate nationallicence maltosyl-β-cyclodextrin nationallicence complexation nationallicence α-chymotrypsin-catalyzed hydrolysis nationallicence thermal unfolding nationallicence Matsubara Kazutaka Pharma Research Laboratories, Hoechist Japan Ltd., Kawagoe, 350-11, Sai-tama, Japan aut Ando Yukihiro Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, 862, Kumamoto, Japan aut Irie Tetsumi Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, 862, Kumamoto, Japan aut Uekama Kaneto Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, 862, Kumamoto, Japan aut Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/10(1997-10-01), 1401-1405 0724-8741 14:10<1401 1997 14 11095 https://doi.org/10.1023/A:1012120705408 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1012120705408 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Matsubara Kazutaka Pharma Research Laboratories, Hoechist Japan Ltd., Kawagoe, 350-11, Sai-tama, Japan aut NATIONALLICENCE 700 1- Ando Yukihiro Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, 862, Kumamoto, Japan aut NATIONALLICENCE 700 1- Irie Tetsumi Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, 862, Kumamoto, Japan aut NATIONALLICENCE 700 1- Uekama Kaneto Faculty of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, 862, Kumamoto, Japan aut NATIONALLICENCE 773 0- Pharmaceutical Research Kluwer Academic Publishers-Plenum Publishers 14/10(1997-10-01), 1401-1405 0724-8741 14:10<1401 1997 14 11095 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer