Peptide library

15 residues · 1420 g/mol · 100 atoms

A 15-residue partial sequence derived from a protein found in human gastric juice. Studied in preclinical models for effects on connective tissue and the gastrointestinal lining. The proline-rich middle is why the backbone is modelled in a polyproline-II conformation.

16 residues · 2175 g/mol · 153 atoms

A 16-residue peptide encoded in mitochondrial DNA rather than the nuclear genome. Investigated in metabolic research around glucose handling and the exercise response. Modelled as an alpha helix.

3 residues · 401.91 g/mol · 50 atoms

A tripeptide present in human plasma that binds copper(II) with high affinity. The copper is shown chelated by the terminal amine, the backbone amide nitrogen and the histidine imidazole - the metal position was relaxed to sit about 2 A from each donor.

4 residues · 640 g/mol · 97 atoms

A four-residue peptide with an alternating aromatic-cationic motif that concentrates at the inner mitochondrial membrane. Studied for its interaction with cardiolipin. Residue 2 is 2,6-dimethyltyrosine, modelled with both ring methyls.

39 residues · 4076 g/mol · 289 atoms

A 39-residue lipopeptide studied as a GLP-1 / GIP / glucagon receptor triple agonist. Two positions carry Aib (2 and 20) and one carries alpha-methyl-leucine (13) - all three are modelled. The C20 fatty diacid on Lys17 is a lipid tail and is not drawn, so the mass shown is the peptide backbone only.

Aib at 2 and 20, alpha-methyl-Leu at 13, C20 fatty diacid on Lys17 (tail not shown).

44 residues · 5136 g/mol · 361 atoms

All 44 residues of human growth-hormone-releasing hormone with a trans-3-hexenoyl group on the N-terminal tyrosine, which is what blocks dipeptidyl peptidase cleavage. The largest structure in the set - modelled as an alpha helix.

Synthetic human GHRH(1-44) with a trans-3-hexenoic acid group on Tyr1.

7 residues · 889 g/mol · 126 atoms

The seven-residue actin-binding stretch of thymosin beta-4, N-terminally acetylated. Studied alongside BPC-157 in actin-binding and cell-migration research.

3 residues · 342 g/mol · 55 atoms

The C-terminal tripeptide of alpha-melanocyte-stimulating hormone. Small enough to show every hydrogen, and studied for anti-inflammatory signalling.

4 residues · 3055 g/mol · 208 atoms

A blend rather than a single molecule: GHK-Cu, BPC-157, TB-500 and KPV in one vial. Shown here as a cluster of the four separate structures - they are not bonded to each other.

Four separate peptides in one vial - shown together, not bonded to each other.

663 g/mol · 44 atoms

Not a peptide at all: a redox cofactor built from nicotinamide and adenine, each on a ribose, joined by a diphosphate bridge. Every heavy atom is present - C21 N7 O14 P2 - with hydrogens omitted.

28 residues · 3080 g/mol · 214 atoms

Twenty-eight residues with a single disulfide closing a ring of seventeen, which is most of the molecule, leaving a short tail at each end. Every peptide in this family is built on that same seventeen-residue ring.

Reference entry · not stocked

32 residues · 3464 g/mol · 239 atoms

Thirty-two residues. The ring between its two cysteines is the same size as the one in ANP and overlaps it heavily, but the tails on either side are longer and different. Both are here.

Reference entry · not stocked

22 residues · 2198 g/mol · 151 atoms

Twenty-two residues, and the disulfide closes onto the very last one, so unlike its two relatives here this peptide has no tail behind the ring at all. Putting all three side by side shows the family reduced to its core.

Reference entry · not stocked

27 residues · 2985 g/mol · 210 atoms

Twenty-seven residues named for the histidine it starts with and the methionine it ends with. Cut from the same precursor as VIP, which is also in the library, and built to the same helical plan.

Reference entry · not stocked

14 residues · 1524 g/mol · 108 atoms

Fourteen residues identical to the tail of histone H4. The library already holds buforin, which comes from histone H2A, so two different histones are represented.

Reference entry · not stocked

6 residues · 746 g/mol · 117 atoms

Six residues sharing their last four with neurotensin, which is also here, and cut from the same precursor. The two are made by cutting one protein in two places.

Reference entry · not stocked

9 residues · 1084 g/mol · 75 atoms

Nine residues taken from a stretch of uteroglobin. One of the shorter sequences in this library to have been studied on its own rather than as part of its parent protein.

Reference entry · not stocked

3 residues · 362 g/mol · 48 atoms

Three residues, and the smallest peptide hormone known. It opens with a pyroglutamate ring and closes with an amide, both drawn, so almost none of this molecule is an ordinary chain. Cyclo-His-Pro, which is what is left when this breaks down, is also in the library.

Reference entry · not stocked

11 residues · 1513 g/mol · 108 atoms

Eleven residues carrying the His-Phe-Arg-Trp core that every melanocortin peptide is built around. Alpha-MSH and ACTH 1-24 are also here, and the shared four residues are easy to find in all three.

Reference entry · not stocked

22 residues · 2661 g/mol · 188 atoms

Twenty-two residues, the longest of the three melanocortin-stimulating peptides, with the same His-Phe-Arg-Trp core buried in the middle rather than sitting near an end.

Reference entry · not stocked

23 residues · 2547 g/mol · 181 atoms

Twenty-three residues cut from the same precursor as ghrelin, from the stretch immediately after it. Named for what it was first reported to do, which later work did not settle.

Reference entry · not stocked

9 residues · 1088 g/mol · 78 atoms

Nine residues released from the alpha chain of haemoglobin. The library already holds three peptides cut from the beta chain, so both chains are now represented.

Reference entry · not stocked

36 residues · 4310 g/mol · 306 atoms

Thirty-six residues named for the tyrosine at each end, which is what the two Ys stand for. A gut hormone released after eating, and the only member of its family in the library that starts and ends the same way.

Reference entry · not stocked

36 residues · 4182 g/mol · 294 atoms

Thirty-six residues, exactly the same length as peptide YY and built to the same plan, though it shares fewer than half its positions. Both are here, so how much can change while the shape holds is visible directly.

Reference entry · not stocked

30 residues · 3157 g/mol · 224 atoms

Thirty residues. The first fifteen are identical across every species it has been found in, which is unusual, and the back half is not.

Reference entry · not stocked

8 residues · 1111 g/mol · 160 atoms

Eight residues, the shortest active form. Two arginines and a proline in the back half, which is where the activity sits.

Reference entry · not stocked

20 residues · 2188 g/mol · 153 atoms

Twenty residues. The S is the serine it begins with, which is conserved everywhere it has been found and is required for it to work at all.

Reference entry · not stocked

41 residues · 4758 g/mol · 333 atoms

Forty-one residues in a long helix. The peptide the whole urocortin and sauvagine family is named after, and both of those are also in this library.

Reference entry · not stocked

38 residues · 4138 g/mol · 290 atoms

Thirty-eight residues sharing the family helix while overlapping the original urocortin at fewer than half its positions. Both are here.

Reference entry · not stocked

19 residues · 2387 g/mol · 165 atoms

Nineteen residues with a disulfide closing a ring of nine in the middle, leaving a short tail free at each end.

Reference entry · not stocked