Viktor Mutt

Category	Research
Also known as	Viktor Mutt Karolinska, gut peptide pioneer
Last updated	2026-04-14
Reading time	3 min read
Tags	scientistgut-peptideskarolinskacckvip

Overview

Viktor Mutt (1923–1998) was an Estonian-born Swedish biochemist whose laboratory at the Karolinska Institute in Stockholm identified an extraordinary number of gastrointestinal peptides. Over several decades, Mutt's group purified and sequenced cholecystokinin, secretin, vasoactive intestinal peptide, gastric inhibitory polypeptide, PHM/PHI, peptide YY, neuropeptide Y, galanin, and several others. Few laboratories have contributed so many named peptides to the literature.

Mutt's success was driven by a combination of methodological innovation and persistence. His laboratory processed enormous quantities of porcine intestinal tissue, developed efficient purification schemes, and pioneered a chemical assay for C-terminally amidated peptides that made it possible to detect otherwise overlooked molecules. The amidation assay proved particularly fruitful, because many bioactive peptides — including CCK, PYY, and NPY — share this structural feature.

He worked closely with Erik Jorpes and with a succession of international collaborators, training many of the leading gut peptide researchers of the late twentieth century.

Background

Mutt was born in Tartu, Estonia. His family fled the Soviet invasion of Estonia during World War II and eventually settled in Sweden. He trained in chemistry at Stockholm University and joined Jorpes's laboratory at the Karolinska Institute in the 1950s. When Jorpes retired, Mutt continued and expanded the gut peptide program.

His style was methodical and tissue-based: he and his students were willing to process truckloads of pig intestines to obtain enough starting material for purification. This approach was gradually supplanted by molecular cloning in the 1980s and 1990s, but for several decades it was the dominant way to discover new peptide hormones.

Key Contributions

Purification and sequencing of CCK and demonstration that CCK and pancreozymin are one molecule.
Purification and sequencing of VIP, GIP, secretin, and numerous other gastrointestinal peptides.
Development of a chemical assay for C-terminally amidated peptides, enabling isolation of NPY, PYY, galanin, and others.
Mentorship of Kazuhiko Tatemoto and other peptide chemists who extended the Karolinska program.

Timeline

1923: Born in Tartu, Estonia.
1940s: Family flees to Sweden.
1950s: Joins Erik Jorpes's laboratory at the Karolinska Institute.
1960s: Purifies and sequences secretin and CCK.
1970s: VIP, GIP, and related peptides characterized.
1980s: PYY, NPY, galanin, and others isolated.
1998: Dies in Stockholm.

Modern Relevance

The catalog of peptides purified by Mutt and his collaborators is the foundation of modern gastrointestinal endocrinology. Clinical measurements of CCK, GIP, secretin, VIP, and related peptides; pharmacological use of octreotide, vapreotide, and VIP/secretin receptor agonists; and fundamental research on gut-brain signaling all descend from this work.

Mutt's methodological contributions — particularly systematic mass-action purification and the amidation assay — also illustrate how steady, rigorous biochemical methods can yield sustained scientific returns over decades. Modern peptide-discovery approaches (genome mining, mass spectrometry, bioinformatic prediction) now complement and often replace tissue-based purification, but the peptides Mutt found remain central. See cck-discovery and pyy-discovery for specific stories.