Subject: Are more complex enzymes more likely to be denatured by heat?

I know that some enzymes can withstand higher temperatures than others, 
and that some can return to their proper shape once their surroundings 
have cooled down. I would like to know if larger, more complex enzymes are 
more susceptible to heat than less complex ones, and is it more difficult 
for them to come back to their proper shape? Enzymes are fairly convoluted 
molecules, and I would think that smaller ones, since they are less 
convoluted than most, would be better able to correctly arrange themselves 
after being denatured. I also read that a few enzymes can even survive 
boiling. Are these some of the smallest, or does size matter?

Re: Are more complex enzymes more likely to be denatured by heat?