Mins at Express Jet are 600/100. Saab is right...you are 1/2 way there. I would keep building time until you had 600/100. Then I would ask yourself, "Are you ready for the responsibility of taking 50 lives and transporting them safely around the country, at over 500mph, in bad weather??" If you believe you are ready, then go ahead and apply once you hit 600/100.
For most people, it depends upon their experience. If they learned to fly out of a small uncontrolled field in the middle of nowhere, in all VFR weather, and have spend 350 hours flying skydivers in a C182 in good weather, I would believe the answer is no. If they learned to fly in a busy terminal environment, have several hours of actual IFR, and have spend 350 hours instructing new students, then I would believe the answer is yes. But it is different for everyone. You need to make the call!