Anti-Tubulin Monoclonal antibody, clone 6G7

Variants of tubulin beta 8 class VIII (TUBB8) have been shown to be associated with female infertility characterized by oocyte or embryonic defects. To further investigate the mutational spectrum ofTUBB8and the prevalence of variants, we performed Sanger sequencing ofTUBB8on a total of 115 infertile females who had undergone repeated in vitro fertilization cycles with oocyte or embryonic defects and 200 healthy controls. A total of 31 variants which were absent from the controls were identified in 36 unrelated individuals, accounting for a large proportion of this cohort (31.3%). All of the variants including heterozygous/homozygous missense variants and a heterozygous frameshift insertion variant were at conserved sites and predicted to be deleterious. Besides, these variants had diverse phenotypic effects, including not only oocyte maturation arrest, fertilization failure, and early embryonic arrest, but also multi-pronuclei (MPN) formation, which is a new phenotype associated withTUBB8variants. Overall, this study reveals a large number of variants of theTUBB8gene in infertile females with oocyte or embryonic defects. Our results not only broaden the mutational and phenotypic spectra ofTUBB8variants, but also further confirm the critical role of TUBB8 in oocyte maturation, fertilization, and early embryonic development.

Mertansine, a thiol-containing maytansinoid, is a tubulin inhibitor used as the cytotoxic component of antibody-drug conjugates for the treatment of cancer. Liquid chromatography-tandem mass spectrometry was described for the determination of mertansine in rat plasma. 50-mu L rat plasma sample was pretreated with 25 mu L of 20 mM tris-(2-carboxyethyl)-phosphine, a reducing reagent, and further vortex-mixing with 50 mu L of 50 mM N-ethylmaleimide for 3 min resulted in the alkylation of thiol group in mertansine. Alkylation reaction was stopped by addition of 100 mu L of sildenafil in acetonitrile (200 ng/mL), and following centrifugation, aliquot of the supernatant was analyzed by the selected reaction monitoring mode. The standard curve was linear over the range of 1-1000 ng/mL in rat plasma with the lower limit of quantification level at 1 ng/mL. The intra- and inter-day accuracies and coefficient variations for mertansine at four quality control concentrations were 96.7-113.1% and 2.6-15.0%, respectively. Using this method, the pharmacokinetics of mertansine were evaluated after intravenous administration of mertansine at doses of 0.2, 0.5, and 1 mg/kg to female Sprague Dawley rats.