Varga S, Csermely P, Mullner N, Dux L, Martonosi A
Biochim Biophys Acta. 1987 Jan 26;896(2):187-95. doi: 10.1016/0005-2736(87)90179-9.
The influence of chemical modification on the morphology of crystalline ATPase aggregates was analyzed in sarcoplasmic reticulum (SR) vesicles. The Ca2+-ATPase forms monomer-type (P1) type crystals in the E1 and dimer-type (P2) crystals in the E2 conformation. The P1 type crystals are induced by Ca2+ or lanthanides; P2 type crystals are observed in Ca2+-free media in the presence of vanadate or inorganic phosphate. P1- and P2-type Ca2+-ATPase crystals do not coexist in significant amounts in native sarcoplasmic reticulum membrane. The crystallization of Ca2+-ATPase in the E2 conformation is inhibited by guanidino-group reagents (2,3-butanedione and phenylglyoxal), SH-group reagents, phospholipases C or A2, and detergents, together with inhibition of ATPase activity. Amino-group reagents (fluorescein 5'-isothiocyanate, pyridoxal phosphate and fluorescamine) inhibit ATPase activity but do not interfere with the crystallization of Ca2+-ATPase induced by vanadate. In fluorescamine-treated sarcoplasmic reticulum the vanadate-induced crystals contain significant P1-type regions in addition to the dominant P2 form.
在肌浆网（SR）囊泡中分析了化学修饰对结晶ATP酶聚集体形态的影响。Ca2 + -ATP酶在E1构象中形成单体型（P1）晶体，在E2构象中形成二聚体型（P2）晶体。P1型晶体由Ca2 +或镧系元素诱导；在存在钒酸盐或无机磷酸盐的无Ca2 +培养基中观察到P2型晶体。在天然肌浆网膜中，P1型和P2型Ca2 + -ATP酶晶体不会大量共存。E2构象中Ca2 + -ATP酶的结晶受到胍基试剂（2,3-丁二酮和苯乙二醛）、SH基试剂、磷脂酶C或A2以及去污剂的抑制，同时ATP酶活性也受到抑制。氨基试剂（5'-异硫氰酸荧光素、磷酸吡哆醛和荧光胺）抑制ATP酶活性，但不干扰钒酸盐诱导的Ca2 + -ATP酶结晶。在荧光胺处理的肌浆网中，钒酸盐诱导的晶体除了主要的P2形式外，还含有大量的P1型区域。
