Big Bang Theory's Kaley Cuoco turns on the Hollywood glamour in ruffled white dress as she heads to TV studios in New York

Her Big Bang Theory character Penny is hardly renowned for being at the cutting edge of fashion.

However Kaley Cuoco looked like a Hollywood glamour puss after donning a striking white dress for an appearance on Late Night with David Letterman in New York on Monday.

The 26-year-old gave fans a cheeky smile as she pulled out the skirt of the crumpled silk number as she got a rapturous reception from fans outside the studio.

 And she took heed of the effort they made by generously stopping to sign autographs for the bustling crowd.

The former charmed star look spellbinding in the dress, which had crumpled detailing and a tasteful black belt.

It was a far cry to the tired looking starlet who touched down at JFK Airport in advance of the show yesterday.

  Her hair looked messy and she wore sunglasses to hide her tired eyes as she arrived with boyfriend Bret Bollinger.

Fans of The Big Bang Theory will no doubt be popping the champagne, as the sixth season is set to start in just two days on September 27.

And fans will be keen to find out whether her character's on-off relationship with Leonard, played by Roseanne star Johnny Galecki.

The pair ended the series as a couple, despite Penny turning down a shock proposal by the experimental physicist.