# SCLEROTIN PRECURSORS IN DIPTERANS

> **NIH NIH R01** · UNIVERSITY OF MASSACHUSETTS BOSTON · 1992 · $243,359

## Abstract

It is well known that mosquitoes and other dipterans serve as vectors for
diseases such as malaria, encephalitis, sleeping sickness, yellow fever,
and dengue fever.  In most instances, disease causing organisms not only
successfully penetrate the well protected, hard and tanned exoskeleton of
the insect vector, but also invade their immune system.  Our long term
goals are a) to unravel the structure and mechanism of formation of
crosslinks stabilizing the insect cuticle; b) to examine the biochemistry
of the enzymes involved in sclerotization, wound healing, and melanization;
and c) to study the developmental and regulatory role of these enzymes at
the macromolecular level.  A better understanding of these processes can
eventually lead to the development of new and target oriented insect
control measures.  The specific aims are:  a) to study the enzymology of
cuticular sclerotization; b) to continue model sclerotization studies and
crosslink analysis in dipteran cuticle; and c) to examine the
prophenoloxidase activation and its regulation.  To achieve these goals,
the following studies will be carried out:

Quinone isomerase and quinone methide isomerase - two new enzymes involved
in sclerotization of insect cuticle will be purified and characterized from
S. bullata, D. melanogaster, and Aedes aegypti.  The possible formation of
a metabolon by phenoloxidase - quinone isomerase and quinone methide
isomerase will be evaluated.  The metabolism of dehydro N-beta-
alanyldopamine will be examined by biosynthetic and oxidative studies.
Polyclonal antibodies to prophenoloxidase and quinone isomerase will be
obtained and used to determine the intracellular localization and to
examine the synthesis, processing, and regulation of these enzymes.
Chemical and enzymatic model sclerotization studies will be continued.
Adducts of quinones and quinone methides with small and macromolecular
compounds will be obtained by synthetic and degradative routes and their
structure will be established using UV, IR, and NMR spectroscopic
techniques.  The role of phenoloxidase, quinone isomerase, and other
proteins involved in sclerotization and melanization of insect cuticle will
be evaluated.  The mechanism(s) of activation of prophenoloxidase system in
the hemolymph will be determined.

## Key facts

- **NIH application ID:** 3125859
- **Project number:** 2R01AI014753-13A2
- **Recipient organization:** UNIVERSITY OF MASSACHUSETTS BOSTON
- **SAM.gov UEI:** CGCDJ24JJLZ1
- **Principal Investigator:** Manickam Sugumaran
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $243,359
- **Award type:** 2
- **Project period:** 1978-08-01 → 1995-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3125859

## Citation

> US National Institutes of Health, RePORTER application 3125859, SCLEROTIN PRECURSORS IN DIPTERANS (2R01AI014753-13A2). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3125859. Licensed CC0.

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