Phycobiliproteins and phycobilisomes: the early observations

Abstract

The purpose of this minireview is to highlight the early observations that led to the discovery of the physicochemical properties of the phycobiliproteins, their structure and function, and to their architectural organization in supramolecular complexes, the phycobilisomes. Generally attached on the stromal surface of the thylakoid membranes in both prokaryotic (cyanobacteria) and eukaryotic cells (cyanelles, red algae and cryptomonads), these complexes represent the most abundant soluble proteins and the major light-harvesting antennae for photosynthesis. This review mainly focuses on the years prior to the development of the molecular biology of cyanobacteria that flourished in the 1980s. We refer the reader to the comprehensive and excellent review by Sidler (1994) for more recent discoveries and more detailed literature on this topic.

Characteristics of an R-Phycoerythrin with Two γ Subunits Prepared from Red Macroalga Polysiphonia urceolata

“…These facts provide evidence that α 18.2 and β 20.6 are acidic polypeptides, but γ 31.6 and γ 34.6 which function as linkers in the assembly of R-PE hexamers and PBS rods [ 16 , 19 – 20 , 39 ] are basic ones. The basic feature of the γ subunits is consistent with the common knowledge that linker polypeptides are believed to have basic polypeptide characteristics which were determined based on amino acid sequences of some linker polypeptides [ 6 , 39 – 40 ].…”

Extraction, purification and characterization of phycocyanin from Oscillatoria quadripunctulata—Isolated from the rocky shores of Bet-Dwarka, Gujarat, India

“…Phycobilisomes are large supramolecular aggregates attached to the thylakoid membrane of cyanobacteria (bluegreen algae) and rhodophyta (red algae) that function in light harvesting and energy migration [2][3][4][5]. These phycobilisomes are composed of phycobiliproteins: a family of hydrophilic, brilliantly coloured and stable fluorescent pigment proteins, covalently linked with linear tetrapyrrole prosthetic group (bilins) that, in their functional state, are covalently linked to specific cysteine residues of the proteins [5,6].…”

A Multistate Model for the Fluorescence Response of R‐Phycoerythrin

“…R‐phycoerythrin (R‐PE) is a light‐harvesting protein that absorbs light over a broad range of wavelengths and channels the electromagnetic energy to a photoreactive center. R‐PE and other phycobilin proteins such as allophycocyanin (APC) and B‐phycoerythrin (B‐PE) are found in cyanobacteria and algae and have been studied extensively in the context of photosynthesis (1). Each 240 kDa R‐PE molecule contains more than 34 fluorophores that are linear or “open‐chain” tetrapyrroles of two kinds, phycoerythrobilin (PEB) and phycourobilin (PUB) (2).…”