= E. Rinderknecht
{c}
<E. Rinderknecht> is the first-listed author of primary studies with <R. E. Humbel> that chemically characterized serum polypeptides with insulin-like and growth-promoting activity. Their 1976 amino-terminal sequencing paper compared two preparations then called NSILA I and II and proposed the designation insulin-like growth factor from their biological properties and resemblance to <insulin>.<Amino-terminal sequences of two polypeptides from human serum with nonsuppressible insulin-like and cell-growth-promoting activities: evidence for structural homology with insulin B chain by E. Rinderknecht and R. E. Humbel>[Abstract and author byline]{ref}
Of the first thirty-one residue positions examined, twenty-two were identical between the two polypeptides. That is about $71\%$ identity over the measured segment: substantial similarity, but not identity of the entire molecules. The measured segment and the comparison being made must therefore accompany any percentage. The later complete sequence of <insulin-like growth factor 1> supplied a more extensive chemical description.<The amino acid sequence of human insulin-like growth factor I and its structural homology with proinsulin by E. Rinderknecht and R. E. Humbel>[1978, abstract: complete seventy-residue sequence]{ref}
The scientific contribution is a shift from classifying preparations by their effects to distinguishing specific related <proteins>. Shared biological activity, shared amino-terminal residues and a complete molecular sequence are progressively different kinds of evidence; none should be silently substituted for another.
Back to article page
