Lycopene-Family Carotenoids Confer Thermostability
on Photocomplexes from a New Thermophilic Purple Bacterium
Posted on 2020-06-15 - 14:34
Blastochloris tepida is a newly described thermophilic
purple bacterium containing bacteriochlorophyll b. Using purified light-harvesting 1 reaction center (LH1-RC) core
complexes from Blc. tepida, we compared
the biochemical, spectroscopic, and thermal denaturation properties
of these complexes with those of its mesophilic counterpart, Blc. viridis. Besides their growth temperature optima, a
striking difference between the two species was seen in the carotenoid
composition of their LH1-RC complexes. The more thermostable Blc. tepida complex contained more carotenoids
with longer conjugation lengths (n > 9), such
as
lycopenes (n = 11), and had a total carotenoid content
significantly higher than that of the Blc. viridis complex, irrespective of the light intensity used for growth. The
thermostability of LH1-RCs from both Blc. tepida and Blc. viridis decreased significantly in cells grown in the
presence of diphenylamine, a compound that inhibits the formation
of highly conjugated carotenoids. In contrast to the thermophilic
purple bacterium Thermochromatium tepidum, where
Ca2+ is essential for LH1-RC thermostability, Ca2+ neither was present in nor had any effect on the thermostability
of the Blc. tepida LH1-RC. These
results point to a mechanism that carotenoids with elongated conjugations
enhance hydrophobic interactions with proteins in the Blc.
tepida LH1-RC, thereby allowing the complexes to withstand
thermal denaturation. This conclusion is bolstered by a structural
model of the Blc. tepida LH1-RC and is the first
example of photocomplex thermostability being linked to a carotenoid-based
mechanism.
CITE THIS COLLECTION
DataCiteDataCite
3 Biotech3 Biotech
3D Printing in Medicine3D Printing in Medicine
3D Research3D Research
3D-Printed Materials and Systems3D-Printed Materials and Systems
4OR4OR
AAPG BulletinAAPG Bulletin
AAPS OpenAAPS Open
AAPS PharmSciTechAAPS PharmSciTech
Abhandlungen aus dem Mathematischen Seminar der Universität HamburgAbhandlungen aus dem Mathematischen Seminar der Universität Hamburg
ABI Technik (German)ABI Technik (German)
Academic MedicineAcademic Medicine
Academic PediatricsAcademic Pediatrics
Academic PsychiatryAcademic Psychiatry
Academic QuestionsAcademic Questions
Academy of Management DiscoveriesAcademy of Management Discoveries
Academy of Management JournalAcademy of Management Journal
Academy of Management Learning and EducationAcademy of Management Learning and Education
Academy of Management PerspectivesAcademy of Management Perspectives
Academy of Management ProceedingsAcademy of Management Proceedings
Academy of Management ReviewAcademy of Management Review
Seto, Ryuta; Takaichi, Shinichi; Kurihara, Toshiyuki; Kishi, Rikako; Honda, Mai; Takenaka, Shinji; et al. (2020). Lycopene-Family Carotenoids Confer Thermostability
on Photocomplexes from a New Thermophilic Purple Bacterium. ACS Publications. Collection. https://doi.org/10.1021/acs.biochem.0c00192