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Chlorophyllase was purified 13300-fold from a crude butanol extract of Chlorella regularis. The enzyme clearly recognizes the C132 stereochemistry of chlorophyllous pigments in that it hydrolyzes the a and b (132R) forms but not the a′ and b′ (132S) forms. No enzyme was detected in vivo that specifically hydrolyzes chlorophyll a′.

The effects of trimethylamine‐N‐oxide (TMAO) on the urea‐resistibility of requiem shark myofibrils were investigated, using Ca2+‐ and Mg2+‐ATPase activities as a parameter. Both activities were hardly changed or activated up to 0.6 M urea. In contrast, the two activities both decreased to less than 50% in the presence of TMAO up to 0.5 M. When measured at a 2 : 1 molar ratio of urea and TMAO, Ca2+‐ and Mg2+‐ATPase activities were similar to those in the presence of TMAO alone, indicating that TMAO reduced the urea‐resistibility of myofibrils. Myosin, the most abundant protein in myofibrils, from requiem shark exhibited the effects of urea and TMAO on its Ca2+‐ATPase activity, which was primarily similar to those of myofibrils. However, Ca2+‐ATPase activities in the coexistence of urea and TMAO for actomyosin reconstituted from requiem shark myosin and chicken F‐actin were approximately average of those measured independently in the presence of either urea or TMAO alone. Carp myofibrils, reconstituted actomyosin and myosin, which were used as teleost references, all showed a tendency in the effects of urea and TMAO on Ca2+‐ATPase activities that was similar to those of requiem shark counterparts.

We developed a new patterning method for bacteriorhodopsin (bR) thin films using UV light irradiation. The proton pump function of bR thin films can be deactivated with UV light irradiation. Inactivation of the proton pump function of bR is related to structural changes or photo-bleaching of the retinal in bR using UV light exposure, which was confirmed with absorption and Raman spectroscopy measurements. Utilizing inactivation of the proton pump function with UV light irradiation, we prepared a bR photocell with a stripe-patterned bR thin film and measured its photocurrent response. The new patterning method is applicable to complicated patterning and patterning with a higher spatial resolution, which extends the application of bR thin films as sensor devices.