The histidyl peptides catalysed the phosphorylation of glycerol over the course of three wet-dry cycles (Figure ). We tested a range of histidyl peptide-based catalysts with an N-terminal histidyl residue including histidine, His-NH2, His-Asp, His-Lys and His-Gly-Gly. We tested also the reaction with lower catalyst concentrations of 50 mM for both histidine and His-NH2. In the first cycle, the yields of phosphorylated glycerol in the histidyl catalysed are 11 ± 0.5 %, for the majority of histidyl catalysts with the exception of 100 mM histidine which has yield of 5.7 ± 0.5 % (red bar). The catalysed yield is double that of the uncatalysed reaction which has a yield of 5.1±0.5 % (magenta bar). In the second cycle, the yields of glycerol phosphate from all the histidyl catalysed reaction, including 100 mM histidine, are 20.5±1.0 %. For the uncatalysed reaction the yield is 9.9 ± 0.8 %. Thus, in the second cycle all histidyl peptides produce double the yield of glycerol phosphate compared to the uncatalysed reaction. For the third cycle, the yield in the histidyl catalysed reaction remains higher than the uncatalysed reaction (24.2 ± 3.5 % vs. 11.0 ± 0.6 %) although the increase in yield per cycle begins to level-off.