hi,

some of these papers should give you good idea:

• DNA helix: the importance of being GC-rich

• THE RELATIONSHIP BETWEEN FINE SCALE DNA STRUCTURE, GC CONTENT, AND FUNCTIONAL ELEMENTS IN 1% OF THE HUMAN GENOME

• Importance of GC content, gene density and telomere-specific effects

I hope this helps.

It really depends on what it is you're calculating the GC content of.

If you're talking primers/oligos, the GC content will be the main determinant of the temperature of melting.

If you're talking genomic regions, there are many bioinformatic statistics one may want to compute that will covary with GC content, so failing to take GC content into account may lead to false positive findings.

Care to give more detail about the context of your question?

I am just reading this paper that may also be of your interest: Summarizing and correcting the GC content bias in high-throughput sequencing