Complex sentence: There are more receptors of the surface membrane capable to bind IL-8; the most frequently studied types are the G protein coupled serpentine receptors CXCR1 and CXCR2.
Split into simpler sentences: There are more receptors of the surface membrane capable to bind IL-8. The most frequently studied types are the G protein coupled serpentine receptors CXCR1 and CXCR2.