Rick. I think big companies inheritently don't like Jack's of All Trades. You say you do everything. In a small company, we want people who can do everything. Those people are more valuable because they can wear multiple hats.
In an enterprise environment, there is clear job separation. They don't want people who wear many hats. They want people who focus on one thing and one thing only and who excel at doing just that one thing.
I personally prefer the excitement of not knowing what hat I'll need to wear that day. That's my preference. Other people may prefer the structure and stability of knowing exactly what they're going to work on that day.
I believe that the company's main concern is that you may not stick around because the job is different than what you're used to. In these interviews, I believe it's important to find a way to demonstrate that you seek this type of job and understand the differences between work you've done before.
It may be best to focus only on the strengths that apply to the job description. Tailor your resume and your questions to fit the job. Make sure you are prepared to give answers that tell the interviewers what they want to hear. Most importantly, make sure you actually want to work in this environment and that what you're saying really reflects your desired career path.