ABSTRACT
Cysteine-Rich Secretory Proteins (CRiSPs) are single-chain proteins with molecular masses ranging from 20 to 30 kDa and 16 absolutely conserved cysteine residues. Most reptile venoms appear to contain at least one isoform; CRiSPs are also found in a wide variety of animal tissues in glycosylated or non-glycosylated forms. This chapter presents a broad description of the compiled knowledge about CRiSPs in venoms from venomous snakes and lizards, mainly focusing on their structural features and biochemical/biological properties. Like phospholipases A2 and three-finger toxins, CRiSPs exhibit a diverse array of biological activities with a high level of structural conservatism. Thus, they are an excellent protein family for structure-activity studies. However, as several venom CRiSPs have not yet been assigned specific functions, much effort still needs to be undertaken to improve the knowledge of these molecules, in particular that related to deciphering their role(s) in envenomation.
