ISOLATION OF PHYCOBILISOMES OF ANABAENA VARIABILIS AND FLUORESCENCE IDENTIFICATION OF THEIR INTACTNESS AND DISSOCIATION

Phycobilisomes were isolated from Anabacna variabilis. The cells were disrupted by sonication, treated with 2% Triton X-100 and ultracentrifuged on a sucrose step gradients. Isolation was carried out in 0.9 M Na-K-Phosphate buffer(pH 7.0) at 20℃. Phycobilisomes were recovered in the dark blue band.There are three liquid nitrogen temperature fluorescence emission bands in phyco bilisomes of A. variabilis. In intact phycobilisomes, the relative fluorescence of 686nm was very high, those of 655nm and 666nm were low, the ratios of relative fluorescence of 686nm to 655nm was more than 20, and that of 686nm to 666nm was more than 10. In non-intact phyeobilisomes, the relative fluorescence of 686 nm deereased, those of 655nm and 666mn increased. The room temperature fluorescence emission maximum of intact phycobilisomes was Iocated around 678nm, that of non-intact phycobilisomes was less than 673nm.We suggest that the main criteria to be used in assessing intact phycobilisomes of A. variabilis should be the fluorescence emission around 678nm at room temperature and the ratios of relative fluorescence of 686nm to 655nm and 666nm at liquid nitrogen temperature.Liquid nitrogen temperature fluorescence excitation spectra of F655, F666 and F68 were studied.