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Mycoplasma-induced BALB/c 3T3 collagenase is a mammalian enzyme
Abstract:
A collagenase previously reported to accumulate in the medium of cultures of BALB/c 3T3 cells on infection with Mycoplasma orale [Kluve, Merrick, Stanbridge & Gershman (1981) Nature (London) 292, 855-857] was partially purified and characterized. With regard to purification properties, activation, sensitivity to inhibitors and relative molecular mass the enzyme was similar to previously reported vertebrate collagenases, but could not be unequivocally distinguished from bacterial collagenases. With regard to substrate-specificity and reaction products, however, the collagenase was typical of vertebrate collagenases and distinct from bacterial collagenases. Specifically, the enzyme displayed a preference for type III collagen and type I collagen, a somewhat decreased ability to degrade type II collagen, and a very limited ability to degrade type IV collagen. The initial products of the action of the collagenase on type I collagen were characterized as fragments one-quarter and three-quarters of the length of the intact collagen molecule. Because the properties of the collagenase produced by cultures of mycoplasma-infected BALB/c 3T3 cells are those of a mammalian-type (vertebrate-type) enzyme, we have concluded that the collagenase is a product of the mouse (BALB/c 3T3) genome, and is not produced by the mycoplasma. Therefore it appears that infection of BALB/c 3T3 mouse fibroblasts with Mycoplasma orale induces the mouse cells to produce and secrete collagenase.
Insights
Mycoplasma orale infection of mouse cells induces them to produce a vertebrate-type collagenase. This enzyme, distinct from bacterial collagenases, degrades specific collagen types, indicating a host-cell response to infection.
Area of Science:
- Biochemistry
- Cell Biology
- Microbiology
Background:
- BALB/c 3T3 cells infected with Mycoplasma orale accumulate a collagenase.
- The origin of this collagenase (host vs. microbe) was previously unclear.
Purpose of the Study:
- To partially purify and characterize the collagenase.
- To determine if the collagenase is of mammalian or bacterial origin.
Main Methods:
- Partial purification of the enzyme.
- Characterization of enzyme properties: activation, inhibitor sensitivity, molecular mass, substrate specificity, and reaction products.
- Comparison with known vertebrate and bacterial collagenases.
Main Results:
- The enzyme exhibited properties similar to vertebrate collagenases regarding purification, activation, inhibitor sensitivity, and molecular mass.
- Substrate specificity and reaction products were typical of vertebrate collagenases, distinguishing it from bacterial collagenases.
- The enzyme preferentially degraded type III and type I collagen, with limited activity against type II and type IV collagen.
Conclusions:
- The collagenase produced by mycoplasma-infected BALB/c 3T3 cells is a mammalian-type enzyme.
- The enzyme is a product of the mouse genome, not the mycoplasma.
- Mycoplasma orale infection induces BALB/c 3T3 mouse fibroblasts to produce and secrete collagenase.