Characteristics of retinal-binding proteins from the honeybee retina.
Spectrophotometric studies were performed on two water soluble retinal-binding proteins isolated from honeybee retina. Both pigments, B and C, absorb maximally at about 440 nm. Pigment B is bleached by light to a photoproduct with lambda max at about 370 nm. This pigment reacts with hydroxylamine in the dark to form a product with an absorbance maximum at 360 nm, whereas with cyanoborohydride it reacts only in the light forming a product with lambda max at about 330 nm. Irradiation of pigment C also leads to the formation of a photoproduct with lambda max at about 370 nm but, in contrast to that of pigment B, it reconverts to its 440 nm-form during the following dark period. The results obtained by changing the pH of the extracts support the hypothesis that all-trans retinal binds to each protein via a Schiff base linkage (pK of 8.4). The data are discussed with relation to the physiological role pigment B could play in the visual cycle of honeybees.
D000818:Animals; D001516:Bees; D002352:Carrier Proteins / Q000302:isolation & purification / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D012160:Retina / Q000032:analysis; D012168:Retinal Pigments / Q000502:physiology; D013053:Spectrophotometry
C020932:11-cis-retinal-binding protein; D002352:Carrier Proteins; D012168:Retinal Pigments