Main description This software entry provides the GNU Octave code that accompanies the work entitled: interferENZY: a web-based tool for enzymatic assay validation and standardized kinetic analysis, authored by Maria Filipa Pinto, Antonio Baici, Pedro José Barbosa Pereira, Sandra Macedo-Ribeiro, Annalisa Pastore, Fernando Rocha, and Pedro M. Martins. It has been implemented in the form of a publicly-accessible webserver at https://interferenzy.i3s.up.pt. Abstract Enzymatic assays are widely employed to characterize important allosteric and enzyme modulation effects. The high sensitivity of these assays can represent a serious problem if the occurrence of experimental errors surreptitiously affects the reliability of enzyme kinetics results. We have addressed this problem and found that hidden assay interferences can be unveiled by the graphical representation of progress curves in modified reaction coordinates. To render this analysis accessible to users across all levels of expertise, we have developed a webserver, interferENZY, that allows (i) an unprecedented tight quality-control of experimental data, (ii) the automated identification of small and major assay interferences, and (iii) the estimation of bias-free kinetic parameters. By eliminating the subjectivity factor in kinetic data reporting, interferENZY will contribute to solving the «reproducibility crisis» that currently challenges experimental molecular biology. The interferENZY webserver is freely available (no login required) at https://interferenzy.i3s.up.pt. Contact information: Maria Filipa Pinto (mfpinto@i3s.up.pt) Pedro M. Martins (pmartins@ibmc.up.pt) i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal. Telephone number: +351 226 074 900

Acknowledgements: The work in the context of which this script was created was financed by (i) FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operational Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES) in the framework of projects POCI-01-0145-FEDER-031323 (PTDC/MED-FAR/31323/2017), POCI-01-0145-FEDER-031173 (PTDC/BIA-BFS/31173/2017), POCI-01-0145-FEDER-007274 ("Institute for Research and Innovation in Health Sciences") and POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy), (ii) Base Funding – UIDB/00511/2020 of the Laboratory for Process Engineering, Environment, Biotechnology and Energy – LEPABE – funded by national funds through the FCT/MCTES (PIDDAC), and by (iii) FEDER through Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement in the framework of Project Norte-01-0145-FEDER-000008. PhD fellowship SFRH/BD/109324/2015 (MFP) from FCT is acknowledged. Financial support was provided through the Doctoral Program in Biomedical Sciences (ICBAS-UP).