Development of Novel Mass Spectrum-Based Assay for Simultaneous Detection of 36 Variants in the 14 Pharmacogenetic Genes for the Japanese Population.

Pharmacogenetics (PGx) enhances personalized care, often reducing medical costs, and improving patients' QOL. Unlike single variant analysis, multiplex PGx panel tests can result in applying comprehensive PGx-guided medication to maximize drug efficacy and minimize adverse reactions. Among PGx genes, drug-metabolizing enzymes and drug transporters have significant roles in the efficacy and safety of various pharmacotherapies. In this study, a genotyping panel has been developed for the Japanese population called PGx_JPN panel comprising 36 variants in 14 genes for drug-metabolizing enzymes and drug transporters using a mass spectrometry-based genotyping method, in which all the variants could be analyzed in two wells for multiplex analysis. The verification test exhibited good concordance with the results analyzed using the other standard genotyping methods (microarray, TaqMan assay, or another mass spectrometry-based commercial kit). However, copy number variations such as CYP2D6*5 could not apply to this system. In this study, we demonstrated that the mass spectrometry-based multiplex method could be useful for in the simultaneous genotyping of more than 30 variants, which are essential among the Japanese population in two wells, except for copy number variations. Further study is needed to assess our panel to demonstrate the clinical use of pharmacogenomics for precision medicine in the Japanese population.

Cloning and biochemical characterization of astacin-like squid metalloprotease.

We have cloned four cDNAs encoding astacin-like squid metalloproteases (ALSMs)-I and -II from the Japanese common squid and ALSMs-I and -III from the spear squid. Analysis of the deduced amino acid sequences revealed that ALSMs possess a signal peptide and a pro-sequence followed by an astacin-like catalytic domain and an MAM (meprin, A5 protein, receptor protein-tyrosine phosphatase mu) domain. Phylogenetic analysis revealed that ALSM corresponds to a new cluster of astacins. To analyze the function of the MAM domain, wild-type ALSM and an MAM-truncated mutant were expressed in a baculovirus expression system. The expressed protein encoding full-length ALSM hydrolyzed myosin heavy chain as effectively as native ALSM, whereas the MAM-truncated mutant possessed no protease activity, suggesting that the MAM domain contributes to substrate recognition. ALSM has been isolated from squid liver and mantle muscle. However, analysis with a specific antibody generated against ALSM indicated the presence of ALSM in a wide variety of tissues. ALSM was located in the extracellular matrix of mantle muscle cells. Thus, ALSM is a secreted protease, as are other members of the astacin family. The extracellular localization raises the possibility of substrates other than myosin. The physiological role of ALSM remains unknown, at this time.