| Prota Ventures | Illinois |
| Protabit | California |
| Protagenic Therapeutics, Inc. | |
| Protagonist Therapeutics, Inc. | |
| Protara Therapeutics, Inc. | |
| Protaryx Medical | Maryland |
| ProtaTECH, Inc. | |
| Protea Corporate Consulting, LLC | |
| Protea Digital, LLC | Massachusetts |
| Protea Technology Services, LLC | |
| Protean BioDiagnostics | Florida |
| Protean Logic, Inc. | Colorado |
| Protech | Pennsylvania |
| Protech Associates | Maryland |
| ProTech Compliance, Inc. | Pennsylvania |
| Protech Computer & Internet Services | California |
| ProTech Computing Service | Wyoming |
| ProTech Engineering Services | Maryland |
| ProTech Professional Technical Services, Inc. | Pennsylvania |
| ProTech Security Systems | Arizona |
| ProTech Systems Group, Inc. | Tennessee |
| Protechniq, Inc. | Oregon |
| Protecht, Inc. | Arizona |
| ProtechZi Digital Media | |
| Protect AI | Washington |
| Protected Harbor, Inc. | New York |
| Protected Trust | Florida |
| Protectix, Inc. | California |
| Protectstar, Inc. | Florida |
| Protectus Medical Devices, Inc. | Minnesota |
| Protectus, LLC | Ohio |
| Protedyne Corporation, Inc. | Connecticut |
| Protega Pharmaceuticals, Inc. | |
| Protege | New York |
| Protege Production, LLC | California |
| Protego Biopharma | |
| Protegrity, Inc. | Connecticut |
| Protein Biotechnologies, Inc. | California |
| Protein Dynamic Solutions, Inc. | Massachusetts |
| Protein Evolution | |
| Protein Fluidics, Inc. | California |
| Protein Foundry, LLC | Wisconsin |
| Protein Metrics | Massachusetts |
| Protein Metrics, LLC | |
| Proteinea | |
| ProteinSimple | California |
| Proteintech Group, Inc. | Illinois |
| Proteios Technology | |
| ProTek Devices | Arizona |
| Protenus, Inc. | Maryland |