Neuropeptides

ACTH 4-10

Corticotropin residues 4 to 10

7 residues · 962 Da · 127 atoms

Seven residues from the middle of corticotropin. The same fragment that Semax is built on, shown here without the proline-glycine-proline tail.

Reference entry · not stocked

Alpha-neoendorphin

10 residues · 1228 Da · 88 atoms

Ten residues from the same precursor as the dynorphins, again opening with the shared motif.

Reference entry · not stocked

Beta-endorphin (1-16)

N-terminal sixteen residues

16 residues · 1746 Da · 122 atoms

Sixteen residues from the front of beta-endorphin, beginning with the same four as the enkephalins. The full peptide is 31 residues; this is the part that carries the binding motif.

Reference entry · not stocked

Beta-neoendorphin

Alpha-neoendorphin minus its final lysine

9 residues · 1100 Da · 79 atoms

Nine residues. Exactly the alpha form with the terminal lysine removed, which is a single trimming step, and both are here to show it.

Reference entry · not stocked

Casomorphin

Beta-casomorphin-7

7 residues · 790 Da · 112 atoms

Seven residues released from milk protein during digestion. Three prolines in seven force an extended backbone, so it is drawn in a polyproline-II conformation.

Reference entry · not stocked

Cortistatin-14

14 residues · 1721 Da · 121 atoms

Fourteen residues with cysteines at two and thirteen joined by a disulfide, closing most of the chain into a ring. Structurally close to somatostatin, which is also here.

Reference entry · not stocked

Deltorphin I

Heptapeptide with D-alanine at two

7 residues · 769 Da · 106 atoms

Seven residues with a D-alanine at position two, mirrored here. One of the most receptor-selective opioid peptides known, and the selectivity comes almost entirely from that one inverted residue.

Reference entry · not stocked

Deltorphin II

Deltorphin I with glutamate at four

7 residues · 783 Da · 109 atoms

The same seven positions as deltorphin I with a glutamate where that has an aspartate. One extra carbon is the whole difference, and both are here.

Reference entry · not stocked

Dermenkephalin

Heptapeptide with D-methionine at two

7 residues · 955 Da · 127 atoms

Seven residues with D-methionine at position two. From the same amphibian skin secretions as the deltorphins, and built on the same plan.

Reference entry · not stocked

Dermorphin

Heptapeptide with D-alanine at two

7 residues · 803 Da · 108 atoms

Seven residues with a D-alanine at position two, whose side chain is mirrored here so it reads as distinct from the L form. Originally isolated from amphibian skin.

Reference entry · not stocked

DSIP

Delta sleep inducing peptide

9 residues · 849 Da · 60 atoms

Nine residues with tryptophan at the N-terminus and a run of small residues through the middle. The glycines give the backbone unusual freedom, so an extended conformation is the honest way to draw it.

In our catalogue

Dynorphin A

17 residues · 2148 Da · 153 atoms

Seventeen residues opening with the same tyrosine-glycine-glycine-phenylalanine that every opioid peptide here starts with, then a strongly basic tail of arginines and lysines.

Reference entry · not stocked

Dynorphin B

13 residues · 1571 Da · 112 atoms

Thirteen residues opening with the shared opioid motif. Dynorphin A is also here; the two are cut from the same precursor and diverge after the first six residues.

Reference entry · not stocked

Endomorphin-1

Tyr-Pro-Trp-Phe amide

4 residues · 611 Da · 83 atoms

Four residues, three of them aromatic. Unusual among opioid peptides in not starting with the tyrosine-glycine-glycine-phenylalanine motif, yet binding more tightly than those that do.

Reference entry · not stocked

Endomorphin-2

Tyr-Pro-Phe-Phe amide

4 residues · 572 Da · 79 atoms

Four residues, differing from endomorphin-1 by a single tryptophan becoming phenylalanine. Both are in the library.

Reference entry · not stocked

Galanin (1-30)

30 residues · 3157 Da · 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

Gluten exorphin

5 residues · 600 Da · 80 atoms

Five residues released from wheat gluten during digestion. Two tyrosines side by side carry most of the mass.

Reference entry · not stocked

Hemopressin

9 residues · 1088 Da · 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

Hemorphin-7

10 residues · 1309 Da · 94 atoms

Ten residues released from the beta chain of haemoglobin during digestion. Two shorter members of the same family are in the library.

Reference entry · not stocked

Leu-enkephalin

5 residues · 556 Da · 77 atoms

The same five positions as met-enkephalin with leucine in place of methionine at the end. Putting the two together shows how little separates them.

Reference entry · not stocked

Met-enkephalin

5 residues · 574 Da · 75 atoms

Five residues. One of the two shortest opioid peptides the body makes, and the tyrosine at the front is the part that binds. Small enough to show every hydrogen.

Reference entry · not stocked

Morphiceptin

Beta-casomorphin-4 amide

4 residues · 522 Da · 73 atoms

Four residues derived from milk protein, and one residue different again from endomorphin-2. Three closely related tetrapeptides sit together here.

Reference entry · not stocked

N-Acetyl Selank

Selank with an acetyl cap

7 residues · 794 Da · 117 atoms

Selank with an acetyl group on the N-terminus. Three prolines in seven residues keep the backbone extended.

Reference entry · not stocked

N-Acetyl Selank Amidate

Capped at both ends

7 residues · 793 Da · 118 atoms

Selank capped at both ends, acetyl at one and amide at the other.

Reference entry · not stocked

N-Acetyl Semax

Semax with an acetyl cap

7 residues · 856 Da · 112 atoms

Semax with an acetyl group on the N-terminus, which is drawn. The cap is there to slow enzymatic breakdown at that end of the chain.

Reference entry · not stocked

N-Acetyl Semax Amidate

Capped at both ends

7 residues · 855 Da · 113 atoms

Semax with both ends capped: an acetyl at the N-terminus and an amide at the C-terminus. Both are drawn, and the difference from the plain form is one oxygen.

Reference entry · not stocked

Neuropeptide S

20 residues · 2188 Da · 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

Neurotensin

13 residues · 1673 Da · 119 atoms

Thirteen residues opening with a pyroglutamate ring and ending in a run of hydrophobic side chains, which is the part that binds.

Reference entry · not stocked

Nociceptin

17 residues · 1809 Da · 128 atoms

Seventeen residues that look like an opioid peptide but begin with phenylalanine rather than tyrosine, which is exactly why it does not act at the classical receptors.

Reference entry · not stocked

Orexin B

28 residues · 2899 Da · 203 atoms

Twenty-eight residues forming two short helices. Unlike orexin A it carries no disulfides, which is why it can be drawn straightforwardly here.

Reference entry · not stocked

PACAP-27

Pituitary adenylate cyclase activating polypeptide

27 residues · 3148 Da · 222 atoms

Twenty-seven residues, strongly helical through the second half. Closely related to VIP, which is also in this library, and the two are worth comparing.

Reference entry · not stocked

Selank

Tuftsin analogue with a Pro-Gly-Pro tail

7 residues · 752 Da · 112 atoms

Seven residues, built from the tuftsin fragment with the same proline-glycine-proline extension found in Semax. Three prolines in a chain of seven forces an extended backbone.

In our catalogue

Semax

ACTH 4-7 with a Pro-Gly-Pro tail

7 residues · 814 Da · 107 atoms

A seven-residue peptide: the four-residue ACTH fragment with a proline-glycine-proline extension. The proline-rich tail is why the backbone is modelled in a polyproline-II conformation rather than a helix.

In our catalogue

Tynorphin

5 residues · 663 Da · 94 atoms

Five residues, the shortest of the three haemoglobin-derived peptides here. Lining all three up shows the same stretch trimmed to different lengths.

Reference entry · not stocked

Valorphin

7 residues · 892 Da · 125 atoms

Seven residues, a shorter cut of the same haemoglobin stretch that hemorphin-7 comes from.

Reference entry · not stocked