Calcitonin gene-related peptide (CGRP) is a putative novel neuropeptide predicted on the basis of alternative RNA processing events of primary transcripts of the calcitonin gene. Distinct mRNAs encoding either calcitonin or CGRP are generated from the calcitonin gene RNA transcript in what appears to be a tissue-specific manner. The predicted peptide has now been detected immunocytochemically in discrete regions of the central and peripheral nervous systems and potent in vivo actions have been reported for centrally and peripherally administered synthetic CGRP. However, so far there is no evidence that CGRP is secreted or released by intact cells. The present experiments investigated the possible secretion of CGRP in vitro using primary dispersed cell cultures of the adult rat trigeminal ganglion, which previously has been found to contain large amounts of CGRP mRNA (ref. 2). We report here that immunoreactive CGRP is spontaneously released by cultured trigeminal ganglion cells and that secretion is stimulated by incubation in high potassium medium in a calcium-dependent fashion. Chromatographic characterization of the secreted CGRP-like immunoreactivity (CGRP-LI) isolated only one molecular form which appears to be similar or identical to the predicted rat CGRP (1-37).

The actions of the neurotransmitter adenosine are mediated by a family of high‐affinity, G protein‐coupled receptors. We have characterized the gene for the human A2a subtype of adenosine receptor (hA2aR) and determined levels of A2aR mRNA in human brain regions and nonneural tissues. Human genomic Southern blot analysis demonstrates the presence of a single gene encoding the hA2aR located on chromosome 22. Two overlapping cosmids containing the hA2aR gene were isolated from a chromosome 22 library and characterized. Southern blot and sequence analyses demonstrate that the hA2aR gene spans ∼9–10 kb with a single intron interrupting the coding sequence between the regions encoding transmembrane domains III and IV. The sequence of the hA2aR gene diverged from the reported cDNA structure in the 5′ untranslated region. This divergence appears to result from an artifact in the construction of the original cDNA library. By northern blot analysis, high expression of the hA2aR gene was identified in the caudate nucleus with low levels of expression in other brain regions. High expression was also seen in immune tissues; lesser A2aR expression was detected in heart and lung. The gene for the A2a subtype of receptor for the neurotransmitter adenosine falls in the class of intron containing G protein‐coupled receptor genes. Expression in the basal ganglia is consistent with a role for the hA2aR in motor control. Activation of the A2aR may also regulate immune responses and cardiopulmonary function.

An animal model for the adenosine deaminase (ADase) conversion proteins has been demonstrated in various rabbit tissues. These proteins bind specifically to the type C rabbit or calf ADase (Mr ~35 000) to produce a large increase in molecular weight with no significant effect on maximum velocity. Kidney displayed the greatest conversion activity, followed by ileum and lung. The latter tissues were shown to have all of their ADase present as high molecular weight enzyme and were also characterized by low specific ADase activity. The molecular weight of endogenous kidney ADase was estimated as 295 000 by gel filtration chromatography. No strict correlation between the level of specific ADase activity and quantity of either ADase or free conversion protein was observed. The kidney conversion protein was purified over 1700-fold to apparent homogeneity. Purification steps included gel filtration chromatography followed either by specific .A.denosine deaminase (EC 3.5.4.4) is a widely distributed aminohydrolase that catalyzes the irreversible hydrolysis of adenosine to inosine and ammonia. This enzyme is of special interest since much evidence supports a role in the regulation of cellular growth and differentiation [e.g., Ishii & Green (1973), Meuwissen et al. (1975), and Trotta & Balis (1978)].In particular, clinical and in vitro studies strongly suggest a causal relationship between the genetically determined absence of this enzyme activity and the severe combined immunodeficiency disease, which is characterized by severe defects in cellular and humoral immunity (Dissing & Knudsen, 1972;Giblett et al., 1972;Meuwissen et al., 1975). The enzyme is of additional importance because it can also catalyze the deamination and consequent inactivation of several potent antitumor and antiviral nucleosides (Brink & LePage, 1964Schabel, 1968;Plunkett & Cohen, 1975).Several variants of ADase1 that can be distinguished on the basis of charge and/or molecular weight have been described.The cytosolic vertebrate enzyme can be classified according to three molecular weight ranges: (1) >200000 (type A); (2) ~100 000 (type B); (3) ~35 000 (type C) (Ma & Fisher, 1968. In man erythrocytes contain exclusively type C enzyme, whereas varying amounts of the type A form are generally found in other tissues (Akedo et al., 1970(Akedo et al., , 1972Edwards et al., 1971). Proteins have been described in certain human tissues which can cause a type C to type A conversion (Nishihara et al., 1973; Schrader & Stacy, 1977;Dadonna & Kelley, 1978). These conversion proteins (Mr ~200 000) are apparently incorporated into the quaternary structure of the high molecular weight enzyme to form an oligomer fFrom the Memorial Sloan-

Xylanase producing thermophilic actinomycetes strain B42 was isolated from bagasse. This strain was enriched on oat spelt xylan agar medium and screened onto xylan-congo red agar plate by the xylanolysis method. The Phylogenetic analysis using 16S rDNA sequence data showed that strain B42 had the highest homology (99.0%) with Laceyella sacchari and it was named as L. sacchari strain B42. L. sacchari strain B42 xylanase was purified to study its biochemical characteristics and its biobleaching efficiency. The partial purification of xylanase using acetone fractionation (at 1:3.0 ratio) gave 2.51 fold purification and the recovery of 88%. Further purification of the partially purified xylanase using DEAE-Sephadex A-50 and G-100 column chromatography gave 11.41 fold purification and 22.80% yield with the specific activity of 1750.0 U/mg. The molecular mass of the purified xylanase was ~30.0 kDa, as analyzed by SDS/PAGE and zymogram. The enzyme reactions followed Michaelis-Menten kinetics with Km and Vmax values of 4.166 mM and 3787.87µmole/min/ml/mg, respectively, as obtained from a Lineweaver-Burk plot. The optimal temperature of the enzyme was 70°C. The enzyme retained 72% of its activity at 70°C and 48% activity at 80°C after 6 h of incubation. The half life (t 1/2 ) of purified xylanase was 6 h at 80°C. The optimal pH of xylanase activity was 10.0 and enzyme appeared to be stable over a broad pH range (pH, 11.0 to 12.0) under the assay conditions. Approximately 68 and 64% of the original activity was retained after 5 h of incubation at pH, 10.0 and 11.0, respectively. The enzymatic biobleaching of kraft pulp reduced ~26% kappa number, decreased 1.68% lignin content and released 24 fold reducing sugars. The enzyme also released sufficient amount of phenolic and hydrophobic compounds. The UV absorption spectrum of the compounds released by enzymatic treatment at 280 nm indicates the presence of lignin in the released coloring matter.