The blood pigment haemoglobin is a compound which can be split by diverse methods into its constituents, pigment and protein.

If we introduce iron complexly into ooporphyrin, we obtain haemin.

Coproporphyrin in particular is widespread; traces are present in normal urine and also in yeast. In special cultures, yeast can be made to produce considerable quantities of coproporphyrin.

In cases of porphyria, a minor disease, the patient excretes large quantities of porphyrins.

In 1970, I had begun work on the basic pancreatic trypsin inhibitor which has later become the model compound for the development of protein NMR, molecular dynamics, and experimental folding studies in other laboratories.

Diabetes and hypertension can scar the blood vessels that go to the kidney thereby spilling protein.