Hepatic lipase often found bound to HSPG, heparan sulfate proteoglycans (HSPG), keeping HL inactive and unable to bind to HDL (high density lipoprotein) or IDL (intermediate density lipoprotein). When it is free in the bloodstream, however, it is found associated with HDL to maintain it inactive. This is because the triacylglycerides in HDL serve as a substrate, but the lipoprotein contains proteins around the triacylglycerides that can prevent the triacylglycerides from being broken down by HL. One of the principal functions of hepatic lipase is to convert intermediate-density lipoprotein (IDL) to low-density lipoprotein (LDL). Hepatic lipase thus plays an important role in
Collateral adjective Collateral adjective A collateral adjective is an adjective that is identified with a particular noun in meaning, but that is not derived from that noun. For example, the word "bovine" is considered the adjectival equivalent of the noun "cow", but it is derived from a different word, which happens to be the Latin word for "cow". Similarly, "lunar" serves as an adjective to describe attributes of the Moon; "moon" comes from Old English "mōna" "moon" and "lunar" from Latin "luna" "moon". The adjective "thermal" and the noun "heat" have a similar semantic relationship. As in these examples, the collateral adjective