Microbial community assembly patterns at the species level in different parts of the medium temperature Daqu during fermentation.

Medium-temperature Daqu (MT-Daqu) serves as a crucial saccharifying and fermentation agent in the production of strong-flavor Baijiu. Due to the spatial heterogeneity of solid fermentation, significant differences occurred in the fermentation state and appearance features in different parts of Daqu during fermentation. Currently, the understanding of the underlying mechanism behind this phenomenon remains limited.

Characterization of chemoreceptive protein binding to an oviposition stimulant using a fluorescent micro-binding assay in a butterfly.

A native female-specific chemoreceptive protein of a swallowtail butterfly [oviposition stimulant binding protein (OSBP)] was shown to specifically bind to aristolochic acid, a main stimulant for oviposition from its host plant. Oviposition stimulants are recognized by chemoreceptive organs of insects. OSBP isolated previously from the chemoreceptive organs was assumed to bind to an oviposition stimulant.

Analogue chromophore study of the influence of electronic perturbation on color regulation of photoactive yellow protein.

We report a unique lambdamax shift of the absorption maximum of a photoactive yellow protein (PYP) analogue reconstituted with a fluorinated chromophore (F-PYP). The difference in lambdamax between the free chromophore and the protein was significantly larger than that with the native chromophore. We concluded that the unusual lambdamax shift is caused by the electronegative character of the fluorine atom and not by steric hindrance.

Constraints of opsin structure on the ligand-binding site: studies with ring-fused retinals.

Ring-fused retinal analogs were designed to examine the hula-twist mode of the photoisomerization of the 9-cis retinylidene chromophore. Two 9-cis retinal analogs, the C11-C13 five-membered ring-fused and the C12-C14 five-membered ring-fused retinal derivatives, formed the pigments with opsin. The C11-C13 ring-fused analog was isomerized to a relaxed all-trans chromophore (lambda(max) > 400 nm) at even -269 degrees C and the Schiff base was kept protonated at 0 degrees C.

Bacteriorhodopsin analog regenerated with 13-desmethyl-13-iodoretinal.

The retinal analog 13-desmethyl-13-iodoretinal (13-iodoretinal) was newly synthesized and incorporated into apomembranes to reconstitute bacteriorhodopsin analog 13-I-bR. The absorption maximum was 598 nm and 97% of the chromophore was an all-trans isomer in the dark- and light-adapted state. Upon flash illumination, 13-I-bR underwent a transient spectral change in which a shorter wavelength intermediate (lambda(max) = 426 nm) similar to the M species of the native bR developed.