Essential primary amino groups of ribulose bisphosphate carboxylase/oxygenase indicated by reaction with pyridoxal 5′-phosphate

Isolation, characterization, and crystallization of ribulosebisphosphate carboxylase from autotrophically grown Rhodospirillum rubrum

“…Similarities between the R. rubrum and spinach carboxylases include an absolute requirement for Mg2" and a time-dependent, Mg2+-dependent inactivation by carboxyribitol bisphosphate, a transition-state analog (55). Affinity labeling studies with 3-bromo-1,4-dihydroxy-2butanone 1,4-bisphosphate (37, 50, 60) and pyridoxal phosphate (39,73,74) indicate striking correspondence between the R. rubrum and spinach carboxylases. These similarities are consistent with the derivation of R. rubrum and spinach Rbl-P2 carboxylases from a common ancestral gene.…”

Photorespiration — still unavoidable?

“…Among these are the carboxylase transition state analogue, carboxyribitol-1,5-bisphosphate [33][34][35], the substrate analogue xylitol-1,5-bisphosphate [36] and the affinity labels N-bromoacetylethanolamine phosphate [37] and pyridoxal-5'-phosphate [38]. The inhibition or inactivation elicited by these reagents is the same for the carboxylase as it is for the oxygenase.…”

Activation of spinach ribulose bisphosphate carboxylase by pyridoxal phosphate

“…Lastly, it was proposed that CO1 (when presented as HC03-) protected the spinach enzyme from Pxl-P inactivation [4,9]. This effect was attributed to competition between COz and Pxl-P for covalent bond formation of the c-amino group of a lysyl residue.…”

“…This effect was attributed to competition between COz and Pxl-P for covalent bond formation of the c-amino group of a lysyl residue. Nevertheless, these workers clearly show that potassium chloride is nearly as effective a protectant against Schiff base formation as HC03-( [9], table 1). This latter result is consistent with our experience that inorganic anions protect against Pxl-P inactivation of the Rhs.…”

“…RuBP carboxylase activity was measured as in [9] except that dithiothreitol was omitted from the assays and incubations because it was shown to have little effect. Otherwise, all incubations were performed in 0.1 M KOH-bicine buffer (pF-I 8.0) and 0.2 mM NazEDTA at 30°C with the noted additions.…”