proto-, prot- +

(Greek: first; foremost, front, earliest form of, original, primitive; chief, principal; usually used as a prefix)

A unicellular or non-cellular animal organism; protozoon (singular); protozoa (plural).
A cell that has a phagocytic action on protozoa; that is, the ingestive action of phagocytes that are specialized cells that ingest and usually destroy foreign particulate matter or microorganisms.
In biology, pollinated by Protozoa or other microscopic animals, as in some aquatic plants.
This word applies to a term called malariotherapy which was used between 1917-1950 for the treatment of syphilis.

In 1917, Julius Wagner von Jauregg (Austrian psychiatrist and neurologist) began inoculating paretics (psychosis associated with neurosyphilis) with blood from patients with benign tertian malaria caused by Plasmodium vivax (protozoan parasite that causes vivax malaria). The elevated temperature of the body caused by the malaria parasite killed the temperature sensitive Treponema pallidum (a microscopic bacterial organism that causes syphilis).

Institutions for malariotherapy rapidly spread throughout Europe and the technique was also adopted in several centers in the United States. In this way, thousands of syphilitics were saved from a sure and agonizing death.

—Compiled essentially from information located in the
The Malaria Capers; by Robert S. Desowitz;
W.W. Norton & Company; New York: 1991; pages 128-130.
Any glycoprotein containing sialic acid.

A glycoprotein is a molecule that consists of a carbohydrate plus a protein. Glycoproteins play essential roles in the body; for example, in the immune system almost all of the key molecules involved in the immune response are glycoproteins.

test protocol
A document laying down in precise detail the tests which must be performed to determine the safety of a substance, agent, or procedure in the course of clinical, experimental, or pharmacological studies.
therapist-driven protocol
A patient care plan initiated and carried out by a respiratory care practitioner with the approval of a hospital medical staff.
zymoprotein (s) (noun), zymoproteins (pl)
Any protein that also functions as an enzyme: Nancy found out that a zymoprotein can also perform or act as an organic compound produced by cells and which behaves as a catalyst.