Before revision:  Here first the same model kt-MT attachment is subjected to external tension that is ramped up till the attachment gets ruptured; the trend of variation of the rupture force distribution with increasing loading rate is consistent with that displayed by the catch bonds formed in some other ligand-receptor systems{\it  {\it   .
After revision:  Here first the same model kt-MT attachment is subjected to external tension that increases linearly with time until rupture occurs. In our{\it {\it .