Anti-delta II tubulin (C-terminal) polyclonal antibody

Plocabulin is a novel microtubule (MT) destabilizer agent with potent antineoplastic activity. This compound binds to the maytansine site at the longitudinal interface between tubulin dimers and exerts a hinge-like effect that disrupts normal microtubule assembly. Plocabulin has emerged as a valuable model for the rational design of novel MT destabilizers because of its unique structural and mechanistic features. To make progress on this matter, detailed molecular-level understanding of the ligand-protein interactions responsible for plocabulin association and the conformation and energetic effects arising from plocabulin binding on the longitudinal interaction between tubulin dimers must be provided. In this work, fully atomistic MD simulations and MM/GBSA binding free-energy calculations were used to examine the association of plocabulin to one or two tubulin dimers in longitudinal arrangement. Our results revealed that plocabulin binding is favored by the addition of a second tubulin dimer and that this ligand promotes the assembly of curved tetrameric arrangements with strengthened longitudinal interdimeric interactions compared to ligand-free systems. The applicability of these findings to the rational discovery of novel MT destabilizers was tested using MD and MM/GBSA calculations as filtering tools to narrow the results of virtual screening among an FDA-approved drug database. Our results confirmed that tight-binding ligands do not necessarily exert the expected conformational and energetic effects on longitudinal tubulin-tubulin interactions, which is a matter to consider in future design strategies.

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.