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The methylene unit resolution of the phospholipids, lipid A palmitoyltransferase PagP is determined by the hydrocarbon rules, a 16-carbon saturated acyl-chain binding pocket buried with the transmembrane [beta]-barrel structure. It is found that substitution of Gly88 lining the floor of the hydrocarbon ruler with Ala or Met makes the enzyme select specifically 15 or 12 carbon saturated acyl chains, respectively.

The energetic origin of the dual emission properties of green fluorescent protein (GFP) variants by examining the temperature dependence of the steady-state absorption and green fluorescent protein emission is considered. The results indicate that the ratiometric dual emission properties of deGFP mutants are due to the pH-sensitive exited-state proton transfer (ESPT) rate, combined with a modulation of the ground-state neutral and anionic chromophore populations with pH.

Research has been conducted on green fluorescent protein with dual steady-state emission properties. The study of the excited-state dynamics of the protein's dual emission variants carried out via the use of ultrafast fluorescence upconversion spectroscopy is presented.

Results point out that an excitonic origin for the red-most states of the chlorophylls at 683 and 690 nanometers are localized to the CP47 pigment-protein complex of the photosystem II. The lowest state absorbs at 690 nanometer and contain one chlorophyll, whereas the other red state absorbs maximally at 683 nanometer and contain three chlorophylls.

Research has been conducted on Synechocystis histidine-tagged photosystem II core complexes. Results indicate that the preparations of these complexes are characterized by the multicomponent decay kinetics.

Research has been conducted on the photosystem II water-oxidising complex's S (sub)3 state. The study of this complex has been carried out via the EPR spectroscopy and the characteristic EPR signals and the equilibria among the excited S (sub)3 state transients have been observed and discussed.

Research has been conducted on the S (sub)3 oxidation state signals. The signal formation correlated with the decay of the S (sub)3-state signals and the comparison of the long-term incubation with the near-IR excitation at liquid-helium temperatures are discussed.

At least three chlorophyll triplet populations are present in thylakoids that are associated with photosystem II as shown by fluorescence-detected magnetic resonance spectrosopy. The triplets are seen in aerated samples and are formed under nonreducing redox conditions with two generating in the core complex(es) and the other in the external antenna.

Transition-state analog inhibitors containing 3,4-dihydro analogs in place of the 4-hydroxyl group are bound by the cytidine deaminase less tightly due to the presence of a trapped water molecule at the active site, reducing contact favorability. The analog complex's transition state is stabilized by the retention of the binding energies in the trapped water molecule while the binding affinity of the 4-hydroxyl group is greater, though not completely due to the 4-hydroxyl's absence but also to the effects of the trapped water molecule.

Monitoring of absorbance changes during the bioluminescent reaction of bacterial luciferase, purified from M17 strain of Vibrio harveyi, demonstrated the presence of three sets of isosbestic points and three kinetic phases. Absorbance changes in the kinetic phases and the gradual decline in light emission is observed for the sample mixtures of luciferase-bound flavin 4a-hydroperoxide intermediate with a long-chain isotope effects. The second step preceded photoexcitation of enzyme-bound flavin 4a-hydroxide.

The temperature dependence of the electron spin-lattice relaxation time T1 was measured for the S(sub 0) state of the oxygen-evolving complex in photosystem II and for two dinuclear manganese model complexes by pulse EPR. For the latter complex, an energy separation between the ground and the first excited electronic state was determined.

The characterization of the excited state dynamics of 3'-hydroxyechinenone (hECN) both in solution and bound to the orange carotenoid binding protein (OCP) in order to disclose the effects of hECN -protein interaction on excited states properties of the hECN is reported. The binding-induced conformational change and activation of the intramolecular charge-transfer state that leads to a shortening of hECN lifetime effectively makes the protein-bound hECN a more effective energy dissipator.

Research has been conducted on flavin mononucleotide-binding LOV1 domain of the Phot1-receptor from Chlamydomonas reibhardtii. The authors have replaced LOV1 domain's photoreactive cysteine C57 by methionine, and the results have demonstrated that the photoexcitation of the C57M mutant produces metastable photoproduct which decomposes into a stable paramagnetic species with red-shift absorption.