Proteins bearing the prosthetic group Fe protoporphyrin IX (or closely related groups) are now recognized to function in the transport of oxygen, in the catalytic activation of O~ and H~O~, and in the shuttling of electrons from dehydrogenases tQ the oxygen-activating enzymes. The structure of this prosthetic compound is a complex one. Attention in the past has been focused mainly on the import...

Insertion of Mg2+ into protoporphyrin IX catalysed by the three-subunit enzyme magnesium-protoporphyrin IX chelatase (Mg chelatase) is thought to be a two-step reaction, consisting of activation followed by Mg2+ chelation. The activation step requires ATP and two of the subunits, ChlI and ChlD (I and D respectively), and it has been speculated that this step results in the formation of an I-D-A...

HYPOTHESIS Sex differentially influences heme oxygenase (HO) expression following trauma and hemorrhagic shock. DESIGN Prospective controlled animal study. SETTING A university laboratory. INTERVENTIONS Female Sprague-Dawley rats in the proestrus stage of their estrus cycle and male rats underwent a 5-cm midline laparotomy (ie, induction of soft tissue trauma) and were bled to a mean arte...

A controlled flow of porphyrin metabolites is critical for organisms, but little is known about the control of porphyrin biosynthesis under environmental stress. We monitored transgenic rice (Oryza sativa) plants expressing Myxococcus xanthus protoporphyrinogen oxidase (PPO) for their response to drought stress. Transgenic plants showed significantly improved drought tolerance, as indicated by ...

We investigated the distribution of Zn protoporphyrin IX (ZPP) in Parma ham by using purple LED light and image analysis in order to elucidate the mechanism of ZPP formation. Autofluorescence spectra of Parma ham revealed that ZPP was present in both lean meat and fat, while red emission other than that of ZPP was hardly detected. Although ZPP was found to be distributed widely in Parma ham, it...