GRGDTP carries the same Arg-Gly-Asp integrin recognition motif as GRGDSP but substitutes threonine for serine in the position immediately following the aspartate. The supplied molecular weights differ by roughly 14, consistent with the extra methyl group that distinguishes threonine from serine. That residue is not decorative. The amino acids flanking the RGD triplet contribute to which integrin heterodimers recognise a given peptide, and small changes at these positions shift selectivity across the integrin family rather than simply raising or lowering affinity uniformly. Having both the serine and threonine variants available lets a laboratory test whether a response is driven by the RGD core alone or depends on the flanking context, which a single peptide cannot distinguish. Applications otherwise parallel those of the serine form: soluble competition to inhibit adhesion, or immobilisation to render a surface adhesive. The same practical caution applies, since RGD-mediated inhibition of adhesion to fibronectin has been reported to be temporary rather than sustained, so the observation window should be chosen deliberately. The matched inactive comparator for this peptide is GRGETP (LT1543), in which the aspartate is replaced by glutamate while the threonine is retained. | 