Application Anticipated to R&D of Antibody Drugs and Generic Biotech Drugs
Shimadzu Corporation has released an accurate glycan analyzer capable of quickly analyzing the structure of the biological molecule "glycan." Glycans play an important role in medical research for such applications as diagnosis of cancer and other diseases and development of antibody drugs. This analyzer can measure trace-level (one nanogram) glycan samples (nano means "one billionth") quickly and with high sensitivity.
An glycan is a molecule formed by a chain of "sugars" such as glucose. Approximately 60 % of protein in organisms exists in the form of a bonded glycan. An glycan is called the third chain of life following nucleic acids and proteins. Whereas nucleic acid and proteins are serial straight chains, an glycan is branched, which means it has extremely diverse types and structures. This diversity performs an important role, for example, in the identification of living things and immunization action.
However, an glycan structure cannot easily be analyzed due to its diversity; for example, structre of glycans are different though
their molecular weight is same. For this reason, an glycan structure has been analyzed only by specialists who assign the sugers while
digesting each indivisual glicosidic bond, or combine two or more analysis methods.
To overcome these issues, in 2005, Shimadzu jointly developed with the National Institute of Advanced Industrial Science and Technology and Mitsui Knowledge Industry Co., Ltd. a method of glycan identification using pattern matching of MS spectra. Measurements are performed by a Shimadzu Matrix-Assisted Laser Desorption/Ionization-Quadrupole Ion Trap Time-of-Flight (MALDI-QIT-TOF) Mass Spectrometer. Shimadzu Corporation and Mitsui Knowledge Industry Co., Ltd. have applied their identification method to an AXIMA Resonance and begun sales.
This system comprises the MALDI-QIT-TOF Mass Spectrometer "AXIMA Resonance", an glycan mass spectrum database, search software, and interface software for accessing these system components. The features of this system are as follows.
An MSn spectrum distinctive to structures can be obtained by selecting specific ions from fragmented ions in an glycan and repeatedly fragmenting them. Using this MSn spectrum enables the analysis of an glycan, including the identification of structural isomers of glycan that have been difficult to analyze. This MSn spectrum can be analyzed only on the AXIMA Resonance. This addresses the need for a high-precision structural analysis method at research sites.
The glycan mass spectrum database consists of MSn spectra of glycans of known structure. Using the measured mass spectrum, the search system selects an glycan-derived ion from the database, and proposes this as the MS/MS spectrum precursor ion. After MS/MS spectra measurement, similar operations automatically present precursor ion candidates for measuring MS3 and MS4 spectra, which are required to identify the glycan structure. Because the software presents the information in this way, structural analysis can be easily performed by operators who possess limited knowledge about glycans.
High-sensitivity structural analysis is possible with even a nanogram-level trace glycan sample using the AXIMA Resonance, which has improved the measurement sensitivity of a multistage n-order MS spectrum 20-fold (in-house comparison). Increased sensitivity is essential for the analysis of glycans, a trace component in organisms, and helps improve efficiency in the preparation of samples.
A combination of rapid MALDI mass spectrometry and the easy analysis offered by pattern matching with a database produces results in several minutes, a process that required several hours using conventional methods.
This system allows operators to rapidly and at high sensitivity identify the structural isomers of the structural isomers of glycans, which used to be impossible using conventional methods. Shimadzu Corporation is working to expand sales of this system in public and private research institutions, specifically in the field of research of antibody drugs and generic biotech drugs.