There is no native way to disable profile changes for certain users/groups.
But I can think of an easy way by adjusting main.php of your template. (If it is "easy" for you depends on your PHP skills.)
You could show the "Update Profile" button only for a) users with certain permissions or b) users in certain groups or c) "managers" (
http://wiki.splitbrain.org/wiki:config:local_php#manager) or ....
Example for case (a):
if($conf['useacl'] && $_SERVER['REMOTE_USER'] && ($INFO['perm'] >= 4){
tpl_button('profile');
}
This removes the button for all those users that have lower than "create" permissions.