Photographic compositions, elements and processes using light-activatable enzymes

A photographic element comprising a support having thereon a layer comprising a hydrophilic binder containing:

• (1) a plurality of vesicles comprising phospholipid membranes containing rhodopsin;
• (2) a mixture of enzymes comprising phosphodiesterase and GTPase;
• (3) at least one metal cation selected from the group consisting of Mg.sup.+2 and Mn.sup.+2 ;
• and
• (4) a mixture of nucleotides comprising cyclic-guanosine monophosphate and guanosine triphosphate;
• said element comprising a means for detecting protons.

A process for forming an image comprising:

• (a) imagewise exposing to light having a wavelength of 350 to 600 nm a photosensitive element comprising a support having thereon at least one layer comprising:
• (1) a plurality of vesicles comprising lipid membranes containing rhodopsin;
• (2) a mixture of enzymes comprising phosphodiesterase and GTPase;
• (3) a first triphosphate nucleotide capable of interacting with GTPase to form a cofactor necessary for the activation of phosphodiesterase;
• (4) at least one metal cation selected from the group consisting of Mg.sup.+2 and Mn.sup.+2 ;
• and
• (5) a second cyclic-monophosphate nucleotide capable of being hydrolyzed to produce a proton, said hydrolysis reaction being catalyzed by activated phosphodiesterase, said phosphodiesterase also being activated by rhodopsin exposed by light in the presence of said cofactor and said metal cation;
• (b) detecting said hydrolysis reaction.

A light-sensitive composition comprising a hydrophilic binder containing:

• (1) a plurality of vesicles comprising phospholipid membranes containing rhodopsin;
• (2) a mixture of enzymes comprising phosphodiesterase and GTPase;
• (3) at least one metal cation selected from the group consisting of Mg.sup.+2 and Mn.sup.+2 ;
• (4) a mixture of nucleotides comprising a triphosphate nucleotide capable of interacting with GTPase to form a cofactor necessary for the activation of phosphodiesterase and a cyclic-monophosphate nucleotide capable of being hydrolyzed to produce a proton;
• and
• (5) means for detecting protons.

A process for preparing a light-sensitive composition, said composition comprising a hydrophilic binder containing:

• (1) a plurality of vesicles comprising phospholipid membranes containing rhodopsin;
• (2) a mixture of enzymes comprising phosphodiesterase and GTPase;
• (3) at least one metal cation selected from the group consisting of Mg.sup.+2 and Mn.sup.+2 ;
• (4) a mixture of nucleotides comprising a triphosphate nucleotide capable of interacting with GTPase to form a cofactor necessary for the activation of phosphodiesterase and a cyclic-monophosphate nucleotide capable of being hydrolyzed to form a protein;
• and
• (5) means for detecting proton;
• said process comprising:
• (a) forming a dispersion of vesicles comprising phospholipid membranes containing rhodopsin by:
• (i) isolating rhodopsin from rod outer segment membranes obtained from dark-adapted vertebrate retinae;
• (ii) combining said rhodopsin with a phospholipid and a detergent to form a solution;
• and
• (iii) removing said detergent from said solution to form a dispersion of vesicles;
• (b) isolating said mixture of enzymes by washing rod outer segment membranes obtained from dark-adapted vertebrate retinae with a hypotonic buffer solution to form a solution of said mixture of enzymes;
• and
• (c) combining said solution of enzymes with said dispersion of vesicles of step (a), predetermined amounts of said metal cation, said mixture of nucleotides, the hydrophilic binder, and said means for detecting protons.