@article{04ef7f7112974d62a8f83928efc1a6bb,
title = "Controllable Phycobilin Modification: An Alternative Photoacclimation Response in Cryptophyte Algae",
abstract = "Cryptophyte algae are well-known for their ability to survive under low light conditions using their auxiliary light harvesting antennas, phycobiliproteins. Mainly acting to absorb light where chlorophyll cannot (500-650 nm), phycobiliproteins also play an instrumental role in helping cryptophyte algae respond to changes in light intensity through the process of photoacclimation. Until recently, photoacclimation in cryptophyte algae was only observed as a change in the cellular concentration of phycobiliproteins; however, an additional photoacclimation response was recently discovered that causes shifts in the phycobiliprotein absorbance peaks following growth under red, blue, or green light. Here, we reproduce this newly identified photoacclimation response in two species of cryptophyte algae and elucidate the origin of the response on the protein level. We compare isolated native and photoacclimated phycobiliproteins for these two species using spectroscopy and mass spectrometry, and we report the X-ray structures of each phycobiliprotein and the corresponding photoacclimated complex. We find that neither the protein sequences nor the protein structures are modified by photoacclimation. We conclude that cryptophyte algae change one chromophore in the phycobiliprotein β subunits in response to changes in the spectral quality of light. Ultrafast pump-probe spectroscopy shows that the energy transfer is weakly affected by photoacclimation.",
author = "Spangler, {Leah C.} and Mina Yu and Jeffrey, {Philip D.} and Scholes, {Gregory D.}",
note = "Funding Information: The authors thank Dr. Beverley Green of the Department of Biology at The University of British Columbia for helpful discussion and experimental insights. We also thank Dr. Paul Curmi of the University of New South Wales for useful protein crystallization discussions and for allowing us to compare our native PC577 structure to their previously resolved PC577 crystal structure. The authors wish to thank Dr. Michael Hecht{\textquoteright}s lab in the Chemistry Department of Princeton University for use of their HPLC. Mass spectrometry and CD measurements were performed in the Mass Spectrometry and Biophysics core facility, respectively, in the Department of Chemistry at Princeton University. The protein crystallography measurements of PC577 were obtained in the Protein Crystallography Core of the Molecular Biology Department at Princeton University. Measurements of PE545 were obtained using the AMX and FMX beamlines of the National Synchrotron Light Source II, a United States Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under Contract No. DE-SC0012704. The Center for BioMolecular Structure (CBMS) is primarily supported by the NIH, National Institute of General Medical Sciences (NIGMS) through a Center Core P30 Grant (P30GM133893), and by the DOE Office of Biological and Environmental Research (KP1605010). This work was funded by the Princeton University Writing Center and CIFAR (Canadian Institute for Advanced Research). Dr. Gregory Scholes is a CIFAR fellow. Publisher Copyright: {\textcopyright} 2022 American Chemical Society. All rights reserved.",
year = "2022",
month = mar,
day = "23",
doi = "10.1021/acscentsci.1c01209",
language = "English (US)",
volume = "8",
pages = "340--350",
journal = "ACS Central Science",
issn = "2374-7943",
publisher = "American Chemical Society",
number = "3",
}