Risuteganib: Molecular Structure

Molecular Structure#

Risuteganib is a synthetic linear hexapeptide belonging to the RGD (arginine-glycine-aspartic acid) class of integrin-binding peptides.

Chemical Properties#

Amino Acid Sequence#

The peptide sequence Gly-Arg-Gly-Cya-Thr-Pro contains:

• Glycine (Gly): Small, flexible residues providing conformational flexibility
• Arginine (Arg): Positively charged residue critical for integrin binding (the "R" in RGD)
• Cysteic acid (Cya): Cysteine with the thiol group fully oxidized to a sulfonic acid (-SO3H). This modification provides the negative charge functionally analogous to aspartate (the "D" in RGD)
• Threonine (Thr): Polar residue contributing to peptide conformation
• Proline (Pro): Rigid residue that constrains the C-terminal conformation

The Gly-Arg-Gly-Cya motif is a modified RGD sequence where the cysteic acid replaces the traditional aspartic acid, providing similar charge characteristics while adding a sulfonate group that may enhance integrin binding specificity.

Integrin Binding#

The RGD motif is a well-established integrin recognition sequence found in extracellular matrix proteins such as fibronectin, vitronectin, and fibrinogen. Risuteganib's modified RGD sequence enables it to bind and modulate four integrin heterodimers:

• alphaVbeta3 and alphaVbeta5 (vitronectin receptors)
• alpha5beta1 (fibronectin receptor)
• alphaMbeta2 (complement receptor 3, Mac-1)

Pharmacokinetic Properties#

The relatively long retinal half-life of approximately 21 days allows for extended dosing intervals, which is a practical advantage for patients requiring repeated intravitreal injections.

Stability#

As a small peptide (637.66 Da), risuteganib has favorable stability characteristics for an injectable formulation. The cysteic acid modification (fully oxidized cysteine) eliminates the potential for disulfide bond formation or thiol oxidation that could occur with a free cysteine residue.

Molecular Context#

Risuteganib belongs to the Healing category of research peptides. The molecular properties of Risuteganib determine its pharmacological behavior, including receptor binding, distribution, metabolism, and elimination. Understanding these properties is fundamental to interpreting clinical data and designing research protocols.

Structural Overview#

Risuteganib is characterized as: Risuteganib is a small synthetic linear hexapeptide containing the RGD (arginine-glycine-aspartic acid) integrin-binding motif. The sequence H-Gly-Arg-Gly-Cys(O3H)-Thr-Pro-OH contains a cysteic acid (oxidized cysteine) residue. It has a molecular weight of 637.66 Da and the molecular formula C22H39N9O11S..

Amino Acid Sequence Details#

The amino acid sequence of Risuteganib is: Gly-Arg-Gly-Cya-Thr-Pro. This sequence determines the peptide's three-dimensional structure, receptor binding properties, and biological activity.

Pharmacokinetic Profile#

Half-Life: Approximately 21 days (retinal half-life)

The half-life of a peptide influences dosing frequency, duration of effect, and the clinical utility of the compound. Researchers should consider the half-life when designing experimental protocols.

Related Reading#

• Risuteganib overview and research guide
• Peptides similar to Risuteganib
• Risuteganib research evidence