Most mutant hemoglobins in the database are single amino acid substitutions. Most of the mutant hemoglobins in the database have a different net charge than that of normal hemoglobin Hemoglobin mutations in the database were not evenly distributed, being rarely observed at residues in the active site or at other amino acid residues that are obviously important for oxygen binding. Since most of the mutant hemoglobins in the database are very similar to normal hemoglobin in their overall properties, a single amino acid substitution has little affect on protein structure and activity. Hemoglobin is an indispensable protein from an early age. A mutation causing a major change in hemoglobin structure or activity would usually be lethal, and to be detected, the hemoglobin mutation obviously must not have been lethal.
Most spontaneous mutations change the net charge of hemoglobin.
It is generally formed by the reaction of an aldehyde or ketone and an amine to form an aminal, followed by dehydration to form an imine. A suicide substrate is a compound that binds to an enzyme active site, and is converted by the enzyme to a more reactive form. This then reacts with the enzyme to form a covalent bond in the active site, usually to the serious detriment of the enzyme activity. A vitamin is an enzyme cofactor, or a precursor to an enzyme cofactor, that we are unable to produce in sufficient quantities to meet our metabolic needs. The Merrifield procedure allows peptide synthesis to be done without requring a different purification procedure after each amino acid residue addition.