Its very unlikely but possible. Hardware developers came up with USB a long time before anyone decided to support it. I have seen socket 5 boards with USB ports. If its been around that long then hopefully someone has written a dos TSR that can make use of them. Mind you, USB only took off when windows 95 osr2 happened
Hn, there can't be a "DOS" (btw, DOS means Disk Operative System, so any OS what carries disk support is a DOS -- for a PS2, and even if it was coded, if wouldn't obviously run game coded for a CISC x86 processor, under the R6000 (sic?) MIPS processor of the PS2. Of course, that is why Bocsh(http://bochs.sourceforge.net/) was created. This thing can emulate up to a Pentium, on a variety of platforms, and comes in the sweet and spring fresh scent of open source. ... Of course, emulation comes at a cost of speed, but I belive it can handle a 486 game.
Actually, come to think of it, the first (publically known) emulator ever written for PS2 was intended to become a PC emulator. It was written by Breakpoint (the author of Project Unreality, the first N64 emulator). It apparently never panned out, and as of December 2001, "ps2pc is... well... really not in development anymore."