JBScreen Plus is an additive screen most useful in the optimization of preliminary crystallization conditions. The selection of the additives is based on the Hofmeister series, which reflects the ability of ions to stabilize the structure of proteins. Thus ions can be classified as either kosmotropic or chaotropic. The first having structure stabilizing properties, thus they may assist in, e.g. crystallizing proteins with a high proportion of flexible loop regions. The latter show structure disturbing properties which may assist in the crystallization of large complexes allowing them to re-arrange to form favorable crystal contacts.

JBScreen Plus consists of 5 individual kits, JBScreen Plus Kosmotropic, JBScreen Plus Chaotropic, JBScreen Plus Salts, JBScreen Plus Additives and JBScreen Plus Volatiles, containing 24 different additives each. The ready-to-use reagents are supplied in 1 ml aliquots.

The 96 solutions of JBScreen Plus HTS, comprising the reagents of the kosmotropic, chaotropic, salts and additive kit, are supplied in a sterile deep well block containing 1 ml per well.

Recommended reading

• Herberhold et al. (2004) Effects of Chaotropic and Kosmotropic Cosolvents on the Pressure-Induced Unfolding and Denaturation of Proteins: An FT-IR Study on Staphylococcal Nuclease. Biochemistry 43:3336.
• Batchelor et al. (2004) Impact of protein denaturants and stabilizers on water structure. J. Am. Chem. Soc. 126:1958.
• Boström et al. (2003) Specific ion effects: Why the properties of lysozyme in salt solutions follow a Hofmeister series. Biophys. J. 85:686.
• Uedaira et al. (2001) Role of hydration of polyhydroxy compounds in biological systems. Cell. Mol. Biol. 47:823.
• http://www.lsbu.ac.uk/water/kosmos.html
• Cacace et al. (1997): The Hofmeister series: salt and solvent effects on interfacial phenomena. Quarterly Reviews of Biophysics 30:241.
• Von Hippel et al. (1965) On the Conformational Stability of Globular Proteins: The Effects of Various Electrolytes and Non-electrolytes on the Thermal Ribonuclease Transition. J. Biol. Chem. 240:3909.