Comparative evaluation of bioactivity change of crystalline trypsin during compression by chemoinformatics and 2-D Fourier-transform infrared spectroscopy

Analyst. 2006 Oct;131(10):1116-21. doi: 10.1039/b604299f. Epub 2006 Aug 30.

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.

MeSH terms

  • Animals
  • Calibration
  • Crystallization
  • Informatics
  • Pressure
  • Protein Structure, Secondary
  • Software
  • Spectroscopy, Fourier Transform Infrared / methods*
  • Swine
  • Trypsin / metabolism*

Substances

  • Trypsin