Casey Preston

Learn More
We have measured the decay of chlorophyll a fluorescence at 4 degrees C under anaerobic conditions in stabilized photosystem II reaction center complex isolated from spinach, using multifrequency (2-400 MHz) cross-correlation phase fluorometry. Examination of our data shows that although the fluorescence decay of open reaction centers (i.e., when both the(More)
Enveloped viruses such as HIV and influenza virus (IFV) are enclosed by a membrane which is obtained from an infected host cell. Infection of a new cell begins with joining or " fusion " of the viral and host cell membranes with an end result of a single membrane and the viral nucleocapsid in the host cell cytoplasm. Although membrane fusion is(More)
The diphenylcarbazide(DPC)/Mn2+ assay [Hsu, B.-D., Lee, J.-Y., & Pan, R.-L. (1987) Biochim. Biophys. Acta 890, 89-96] was used to assess the amount of the high-affinity Mn-binding site in manganese-depleted photosystem II (PS II) membrane fragments from spinach and Scenedesmus obliquus. The assay mechanism at high DPC concentration was shown to involve(More)
The "high-affinity Mn-binding site" in Mn-depleted photosystem II (PS II) membrane fragments isolated from Scenedesmus obliquus was examined by using the diphenylcarbazide (DPC)/Mn2+ non-competitive inhibition assay [Preston, C., & Seibert, M. (1991) Biochemistry (preceding paper in this issue)]. Different proteases were used to degrade lumenal surface(More)
In this paper, we investigate the effects of histidyl amino acid modification on high-affinity Mn binding to photosystem II (PSII) using methods similar to those used in the preceding paper [Ghirardi et al. (1998) Biochemistry 37, 0000] for carboxyl amino acid modification. Given the rather low specificity of diethyl pyrocarbonate (DEPC) for histidine(More)
  • 1