Popis: |
Publisher Summary This chapter focuses on the chemical derivatizaton of Ca 2+ -pump protein from skeletal muscle with N-substituted Maleimides and 5-(2-Iodoacetamidoethyl)aminonaphthalene 1-Sulfonate. It has been difficult to achieve selective modification of a particular SH group, which is well-defined in terms of either its location or functional role, as a large number of SH groups are present in Ca 2+ ,Mg 2+ -ATPase of the sarcoplasmic reticulum (12–17 reactive SH groups in an ATPase polypeptide). In spite of the fact that the ATPase molecule has long been known to contain SH groups essential for the functioning of the transport system, and that their number has been suggested to be rather small, they have not yet been identified. SH groups were also utilized occasionally, as a target for covalent attachment of various probes to monitor conformational changes of transport ATPase during its catalytic cycle. The chapter describes simple procedures for selective derivatization of a limited number of specific SH groups with N-ethylmaleimide (MalNEt), and related fluorescent and paramagnetic probes, as well as a procedure for labeling with 5-(2-iodoacetamidoethyl)aminonaphthalene 1-sulfonate (IAEDANS), a fluorescent derivative of iodoacetamide. |