Tadros M H, Frank R, Drews G
J Bacteriol. 1986 Jul;167(1):96-100. doi: 10.1128/jb.167.1.96-100.1986.
Proteinase K and trypsin were used to determine the orientation of the light-harvesting B800-850 alpha and beta polypeptides within the chromatophores (inside-out membrane vesicles) of the mutant strain Y5 of Rhodopseudomonas capsulata. With proteinase K 7 amino acid residues of the B800-850 alpha polypeptide were cleaved off up to position Trp-7--Thr-8 of the N terminus, and 11 residues were cleaved off up to position Leu-11-Ser-12 of the beta chain N terminus. The C termini of the B800-850 alpha and beta polypeptides, including the hydrophobic transmembrane portions, remained intact. It is proposed that the N termini of the alpha and beta subunits, each containing one transmembrane alpha-helical span, are exposed on the cytoplasmic membrane surface and the C termini are exposed to or directed toward the periplasm.
使用蛋白酶K和胰蛋白酶来确定荚膜红假单胞菌突变株Y5的载色体（内向外膜囊泡）中捕光B800 - 850α和β多肽的取向。用蛋白酶K处理后，B800 - 850α多肽的7个氨基酸残基从N端的色氨酸7 - 苏氨酸8位置开始被切除，β链N端的11个残基从亮氨酸11 - 丝氨酸12位置开始被切除。B800 - 850α和β多肽的C端，包括疏水跨膜部分，保持完整。有人提出，α和β亚基的N端各含有一个跨膜α - 螺旋跨度，暴露在细胞质膜表面，而C端暴露于周质或指向周质。
