Properties of the visual pigments of the moth Manduca sexta and the effects of two detergents, digitonin and chaps.
The three known visual pigments (P520, P450, P357) of the moth, Manduca sexta (Lepidoptera, Sphingidae), were extracted in two different detergents (2% digitonin, 6 or 12 mM CHAPS). As is the case in unextracted membranes, the metarhodopsins are quite stable in CHAPS extracts, while in digitonin the metarhodopsins of P520 and P450 decay rapidly at 15 degrees C to opsin and free retinal. The relative absorbance ratios are: 1.0:1.6 (P520:M485), 1.0:1.1 (P450:M485), and 1.0:0.8 (P357:M470). The relative amounts of the visual pigments found in digitonin extracts is 100:25:8 (P520:P450:P357); about 60 picomoles of P520 can be extracted from one Manduca retina.
D000818:Animals; D002793:Cholic Acids; D003902:Detergents; D004072:Digitonin; D005260:Female; D007700:Kinetics; D007915:Lepidoptera / Q000032:analysis*; D008027:Light; D008297:Male; D009036:Moths / Q000032:analysis*; D012168:Retinal Pigments / Q000302:isolation & purification* / Q000528:radiation effects; D012172:Retinaldehyde; D012996:Solutions; D013053:Spectrophotometry; D013501:Surface-Active Agents
D002793:Cholic Acids; D003902:Detergents; D012168:Retinal Pigments; D012996:Solutions; D013501:Surface-Active Agents; D004072:Digitonin; C028213:3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate; D012172:Retinaldehyde