# STUDIES OF IGA PROTEASES OF HAEMOPHILUS INFULUENZAE

> **NIH NIH R01** · TUFTS UNIVERSITY BOSTON · 1988 · $149,413

## Abstract

A wide range of mucosal pathogens produce an enzyme, IgA
protease, that cleaves human IgA1.  We are interested in the role
these enzymes play in virulence and are studying a number of
aspects of their synthesis, secretion and function.  We have cloned
IgA protease genes (iga) from Haemophilus influenzae serotypes b,
c and d and from Neisseria gonorrhoeae.  The cloned genes are
expressed in E.coli leading to production of IgA proteases with the
same specificity as those produced in the parent organisms.
These enzymes cleave the IgA1 substrate at different bonds in the
hinge region.  We intend to characterize the genes by DNA
sequence analysis and to determine the structural basis for their
different specificities.  The IgA proteases are secreted from the
cell and we wish to elucidate the mechanism by which this occurs.
We have evidence that the enzymes are synthesized as precursors
which are processed during secretion.  The identification of
intermediates involved in this process and the mechanism of
processing is a major goal.  In collaboration with Dr. David
Stephens we will look at the role of IgA protease in H.influenzae
infection using a nasopharyngeal tissue explant model.

We have cloned the IgA protease gene from Streptococcus sanguis
and will determine the DNA sequence of this gene to see how its
product is related to the proteases of the Gram negative
organisms indicated above.  We will modify the cloned gene in
order to generate S. sanguis mutants that lack IgA protease.  Such
mutants will be used to look at the effect of iga mutations on
adherence of S. sanguis in a model system.

## Key facts

- **NIH application ID:** 3129949
- **Project number:** 2R01AI020337-04A2
- **Recipient organization:** TUFTS UNIVERSITY BOSTON
- **SAM.gov UEI:** C1F5LNUF7W86
- **Principal Investigator:** ANDREW WRIGHT
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $149,413
- **Award type:** 2
- **Project period:** 1983-08-01 → 1990-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3129949

## Citation

> US National Institutes of Health, RePORTER application 3129949, STUDIES OF IGA PROTEASES OF HAEMOPHILUS INFULUENZAE (2R01AI020337-04A2). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3129949. Licensed CC0.

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