title: Comparative evaluation of bioactivity change of crystalline trypsin during compression by chemoinformatics and 2-D Fourier-transform infrared spectroscopy.
abstract: The purpose of this study is to develop a method of evaluating the enzymatic activity of trypsin in a solid-state based on Fourier transform infrared (FT-IR) spectra using chemoinformatics and two-dimensional (2-D) correlation spectroscopy. Crystalline trypsin powders are compressed at 0-4000 kg cm-2 by a compression/tension tester. The enzymatic activity of trypsin is assayed by the kinetic degradation method. Spectra of 10 calibration sample sets are recorded 3 times with a FT-IR spectrometer. The maximum intensity of FT-IR spectra and enzymatic activity of trypsin decrease as the compression pressure increases. The FT-IR spectra of trypsin samples are subjected to a principal component regression (PCR). A plot of the calibration data obtained is made between the actual and predicted trypsin activity based on a two-component model with gamma2=0.909 (n=30). The regression vector is almost the same as the loading vector for PC1. On the other hand, a generalized two-dimensional (2-D) correlation spectroscopic method is applied to FT-IR spectra of compressed trypsin. The result is consistent with that of the chemoinformatics method. The FT-IR chemoinformatics method allows for solid-state quantitative analysis of the bioactivity of the bulk powder of a polypeptide drug.
authors.affiliation: Research Institute of Pharmaceutical Sciences, Faculty of Pharmacy, Musashino University, Nishi-Tokyo 202-8585, Japan. motsuka@musashino-u.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Otsuka
authors.forename: Yuya
authors.initials: Y
authors.lastname: Fukui
authors.forename: Kuniko
authors.initials: K
authors.lastname: Otsuka
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Ozaki
mesh_terms: D000818:Animals; D002138:Calibration; D003460:Crystallization; D048088:Informatics; D011312:Pressure; D017433:Protein Structure, Secondary; D012984:Software; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013552:Swine; D014357:Trypsin / Q000378:metabolism*
chemical_list: D014357:Trypsin